Physics Chapter on Angle and Velocity
78 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the SI unit of angular velocity?

  • degrees per second (° s-1)
  • radians per minute (rad min-1)
  • radians per second (rad s-1) (correct)
  • meters per second (m s-1)

Which equation correctly relates linear velocity to angular velocity?

  • v = ωr (correct)
  • v = 2πr/T
  • v = s/r
  • v = θ/t

What does periodic time (T) measure?

  • The time taken for an object to travel in a straight line
  • The time taken for angular velocity to change
  • The time taken for an object to accelerate
  • The time taken for one complete revolution or cycle (correct)

What is the SI unit of centripetal acceleration?

<p>m s-2 (D)</p> Signup and view all the answers

How is centripetal force defined in uniform circular motion?

<p>Force required to maintain uniform circular motion towards the center (D)</p> Signup and view all the answers

What is the relationship defined by Newton's Universal Law of Gravitation?

<p>Force is directly proportional to the product of masses and inversely proportional to the square of distance (C)</p> Signup and view all the answers

What type of quantity is angular velocity?

<p>Vector quantity (D)</p> Signup and view all the answers

If an object is travelling in uniform circular motion, it is experiencing which type of acceleration?

<p>Centripetal acceleration (B)</p> Signup and view all the answers

What is the relationship between arc length, radius, and angle in radians?

<p>s = θr (D)</p> Signup and view all the answers

What is the formula that relates the period of orbit, mass, and radius in gravitational scenarios?

<p>T^2 = (4π^2 R^3) / GM (B)</p> Signup and view all the answers

What is the reason astronauts appear weightless while orbiting the Earth?

<p>They are falling at the same rate as their spacecraft. (C)</p> Signup and view all the answers

Given the gravitational constant and mass of the Earth, what is the average radius of the Moon's orbit calculated using Kepler’s Third law?

<p>3.8 × 10^8 m (D)</p> Signup and view all the answers

What is the centripetal force acting on an object in circular motion equal to?

<p>Both B and C (B)</p> Signup and view all the answers

What altitude are geostationary satellites positioned at above the Earth?

<p>36,000 km (A)</p> Signup and view all the answers

How does the horizontal velocity of a satellite prevent it from falling towards Earth?

<p>It maintains a circular motion compensating for gravitational pull. (C)</p> Signup and view all the answers

Which of the following is true about Newton’s law of gravitation?

<p>It is directly proportional to the product of the masses. (B)</p> Signup and view all the answers

What does Kepler's third law indicate about the relationship between the period of orbit and the radius of the orbit?

<p>T^2 is directly proportional to R^3 (B)</p> Signup and view all the answers

What is the acceleration towards the Earth for geostationary satellites?

<p>0.57 m/s² (A)</p> Signup and view all the answers

How is angular velocity related to periodic time and the angle rotated?

<p>Angular velocity ($,\omega$) is defined as the angle rotated ($\theta$) divided by the periodic time ($T$), expressed as $\omega = \frac{\theta}{T}$.</p> Signup and view all the answers

What determines the centripetal acceleration of an object in uniform circular motion?

<p>Centripetal acceleration is determined by the square of the object's speed ($v^2$) divided by the radius ($r$) of the circular path, given by the formula $a_c = \frac{v^2}{r}$.</p> Signup and view all the answers

Explain the role of centripetal force in maintaining circular motion.

<p>Centripetal force is necessary to keep an object moving in a circular path; it acts towards the center of the circle and is calculated as $F_c = \frac{mv^2}{r}$, where $m$ is mass and $v$ is linear velocity.</p> Signup and view all the answers

Relate the orbital speed of a satellite to gravitational force and radius.

<p>The orbital speed ($v$) of a satellite can be expressed as $v = \sqrt{\frac{GM}{r}}$, where $G$ is the gravitational constant, $M$ is the mass of the Earth, and $r$ is the distance from the center of the Earth.</p> Signup and view all the answers

What is the significance of Newton's Universal Law of Gravitation in understanding orbital motion?

<p>Newton's Universal Law of Gravitation states that the force of attraction between two masses is directly proportional to their mass and inversely proportional to the square of the distance between them, which is fundamental for understanding how objects orbit.</p> Signup and view all the answers

Using Kepler’s Third Law, how can you derive the orbital period of a satellite given its radius?

<p>The orbital period can be derived using the formula $T^2 = \frac{4\pi^2 R^3}{GM}$, where $T$ is the period, $R$ is the radius of the orbit, $G$ is the gravitational constant, and $M$ is the mass of the central body.</p> Signup and view all the answers

Explain why geostationary satellites remain in a fixed position relative to the Earth's surface.

<p>Geostationary satellites orbit at about 36,000 km above the Earth with an orbital period of 24 hours, matching the Earth's rotation speed, allowing them to appear stationary above a specific point.</p> Signup and view all the answers

How does the gravitational force exerted on a satellite relate to its centripetal force in circular motion?

<p>The gravitational force acting on the satellite is equal to the centripetal force needed to keep it in circular motion, given by the equation $F_{gravitational} = F_{centripetal}$.</p> Signup and view all the answers

What is the significance of the average radius in calculating orbital mechanics for celestial bodies?

<p>The average radius is critical as it helps determine the gravitational force and the orbital period of the object, as shown in Kepler’s laws and gravitational equations.</p> Signup and view all the answers

Why do astronauts experience weightlessness while orbiting Earth despite being affected by gravity?

<p>Astronauts feel weightless because both they and their spacecraft are in free fall towards Earth at the same rate, creating a state of constant acceleration without a normal force acting on them.</p> Signup and view all the answers

How can you derive the mass of the Earth using Newton’s law of gravitation and the centripetal force equation?

<p>By equating the gravitational force <code>GMm/R^2</code> and the centripetal force <code>mv^2/R</code>, we can isolate <code>M</code>, leading to the formula <code>M=(v^2 R)/G</code>.</p> Signup and view all the answers

What conditions must be met for astronauts to appear weightless while orbiting the Earth?

<p>Astronauts appear weightless because both they and their spacecraft are in free fall, accelerating towards Earth at the same rate.</p> Signup and view all the answers

What is the relationship established by Kepler’s Third Law regarding orbital period and radius?

<p>Kepler’s Third Law states that the square of the orbital period <code>T^2</code> is proportional to the cube of the average radius <code>R^3</code> of the orbit.</p> Signup and view all the answers

Why do geostationary satellites require a specific altitude to maintain their position over a point on Earth?

<p>Geostationary satellites are positioned at approximately 36,000 km altitude to match the Earth's rotation period, allowing them to remain stationary relative to the surface.</p> Signup and view all the answers

How does the gravitational force acting on a satellite relate to its horizontal velocity to maintain orbit?

<p>The gravitational force provides the necessary centripetal force, while the satellite's horizontal velocity counters this pull, enabling it to travel in a stable circular path.</p> Signup and view all the answers

How is angular velocity (ω) related to linear velocity (v) and radius (r)?

<p>Angular velocity is related to linear velocity by the equation $v = heta r$.</p> Signup and view all the answers

What role does centripetal force play in circular motion?

<p>Centripetal force acts toward the center of the circle, maintaining an object's circular motion by continuously changing its direction.</p> Signup and view all the answers

Explain how periodic time (T) relates to angular velocity (ω).

<p>Periodic time is the inverse of angular velocity, given by the equation $T = \frac{2\pi}{\omega}$.</p> Signup and view all the answers

Why is centripetal acceleration considered a vector quantity?

<p>Centripetal acceleration is a vector quantity because it has both direction and magnitude, always pointing towards the center of circular motion.</p> Signup and view all the answers

According to Newton's Universal Law of Gravitation, what factors affect the gravitational force between two masses?

<p>The gravitational force is directly proportional to the product of the masses and inversely proportional to the square of the distance between their centers.</p> Signup and view all the answers

Define resistance in terms of voltage and current. What is its formula?

<p>Resistance (R) is defined as the ratio of voltage (V) across an object to the current (I) flowing through it. The formula is $R = \frac{V}{I}$.</p> Signup and view all the answers

What is the significance of resistivity, and how is it mathematically expressed?

<p>Resistivity quantifies a material's opposition to electric current and is expressed as $\rho = \frac{RA}{l}$, where R is resistance, A is the cross-sectional area, and l is the length.</p> Signup and view all the answers

Explain the impact of electric flow on materials and how it relates to resistance levels.

<p>Electric flow heats materials as electrical potential converts to thermal energy; high resistance results in more energy loss as heat, while low resistance minimizes energy loss.</p> Signup and view all the answers

What is a variable resistor, and how does it function?

<p>A variable resistor, such as a rheostat, allows adjustable resistance by changing the length of the wire through a sliding contact, affecting resistance based on the wire's length.</p> Signup and view all the answers

How can the area of a wire be determined when calculating resistivity?

<p>The area (A) of a circular wire can be calculated using the formula $A = \pi r^2$ for radius or $A = \frac{d^2}{4}$ for diameter.</p> Signup and view all the answers

Calculate the resistivity of a copper wire that is 2.0 m long with a diameter of 1.0 mm and a measured resistance of 0.043 Ω.

<p>1.688 × 10^{-8} Ω m</p> Signup and view all the answers

Using Ohm's Law, find the resistance of a metal wire that has a voltage of 6 V across it and a current of 0.8 A flowing through it.

<p>7.5 Ω</p> Signup and view all the answers

Explain how Joule's Law applies to minimizing energy losses in electrical transmission.

<p>Joule's Law states that heat is proportional to the square of the current (W = I²R), so minimizing current reduces energy losses.</p> Signup and view all the answers

Describe the behavior of current in a parallel circuit and how it differs from a series circuit.

<p>In a parallel circuit, different currents can flow through each branch, while in a series circuit, the current remains the same at every point.</p> Signup and view all the answers

What is the advantage of using thick wires or low-resistivity materials like copper in electrical transmission?

<p>Using thicker wires or low-resistivity materials minimizes resistance, allowing for higher voltages and smaller currents, which reduces heat loss.</p> Signup and view all the answers

What is the total resistance for resistors connected in series?

<p>The total resistance for resistors in series is calculated as $R_T = R_1 + R_2$.</p> Signup and view all the answers

Explain how the current behaves in resistors that are connected in parallel.

<p>In a parallel circuit, the total current is the sum of the currents flowing through each resistor, expressed as $I_T = I_1 + I_2$.</p> Signup and view all the answers

How does a potential divider function in a circuit?

<p>A potential divider is used to split the input voltage across multiple resistors based on their resistance values.</p> Signup and view all the answers

What is the formula for calculating total resistance in parallel circuits?

<p>The total resistance in a parallel circuit is given by $1/R_T = 1/R_1 + 1/R_2$.</p> Signup and view all the answers

Describe the relationship between current and resistance in a series circuit as defined by Ohm's Law.

<p>According to Ohm's Law, the current through each resistor in a series circuit is the same and relates to the voltage and resistance as $I = V/R$.</p> Signup and view all the answers

What role does adjusting the resistor ratio in a potential divider serve?

<p>Adjusting the resistor ratio in a potential divider changes how the total voltage is distributed across the resistors.</p> Signup and view all the answers

What happens to the output voltage when contact C is moved from position A to position B in a circuit with a rheostat?

<p>The output voltage gradually increases from 0 V to match the battery voltage, causing the light bulb to get brighter.</p> Signup and view all the answers

How does temperature affect the resistance of metallic conductors?

<p>Resistance increases with temperature due to increased atomic vibrations that hinder electron flow.</p> Signup and view all the answers

What distinguishes active electrodes from inactive electrodes in electrochemical reactions?

<p>Active electrodes participate in reactions and may change in mass, while inactive electrodes do not engage chemically.</p> Signup and view all the answers

What do the graphs indicate regarding ohmic and non-ohmic behavior in conductive materials?

<p>Graph (a) shows ohmic behavior with current directly proportional to voltage, while Graph (b) indicates non-ohmic behavior with increasing resistance as temperature rises.</p> Signup and view all the answers

What role do ions and electrons play in the conduction of gases?

<p>Ions and electrons serve as charge carriers, allowing current to flow through the gas.</p> Signup and view all the answers

How does ion concentration affect the conductivity of a solution?

<p>Higher ion concentrations lead to increased conductivity in the solution.</p> Signup and view all the answers

What happens in a discharge tube as voltage increases and how is current affected?

<p>Initially, current rises with voltage until a plateau is reached, and then further voltage increases lead to more charge carriers and increased current.</p> Signup and view all the answers

What does it mean if a graph shows a straight line that intersects the x-axis at a positive value?

<p>It indicates that no current flows until a specific voltage threshold, known as back emf, is overcome.</p> Signup and view all the answers

How does lower pressure affect gas conduction?

<p>Lower pressure enhances gas conduction by decreasing resistance.</p> Signup and view all the answers

What occurs in a discharge tube when voltage exceeds a certain threshold?

<p>Higher voltage increases ion energy, creating more ions and boosting the current.</p> Signup and view all the answers

What defines plasma, and why is it referred to as the fourth state of matter?

<p>Plasma is a partially ionized gas made of ions and free electrons, characterized by its electrical conductivity and responsiveness to magnetic fields.</p> Signup and view all the answers

What makes sodium street lamps particularly energy-efficient?

<p>Sodium street lamps convert a high percentage of input energy into visible light.</p> Signup and view all the answers

What does a balanced Wheatstone bridge setup indicate?

<p>A balanced bridge means no current flows through the galvanometer, indicating points B and C are at the same potential.</p> Signup and view all the answers

How can a thermistor be used in a temperature gauge?

<p>A thermistor measures engine temperature to help manage performance effectively.</p> Signup and view all the answers

What role does an LDR play in the function of a smoke alarm?

<p>An LDR detects light changes caused by smoke, triggering the alarm.</p> Signup and view all the answers

What happens to electrons in a cathode ray tube as voltage increases?

<p>Electrons are emitted from the cathode and attracted to the anode, with current increasing until a plateau is reached.</p> Signup and view all the answers

What factor affects the availability of electrons for conduction in a vacuum?

<p>The cathode's temperature and material impact the number of electrons available for conduction.</p> Signup and view all the answers

What is the relationship established in a Wheatstone bridge for resistance calculation?

<p>The relationship is given by the formula $\frac{R_1}{R_2} = \frac{R_3}{R_4}$.</p> Signup and view all the answers

What principle does a Wheatstone bridge operate on, and how does it allow for resistance measurement?

<p>A Wheatstone bridge operates on the principle of balancing two legs of a circuit. It allows for resistance measurement by comparing the ratio of known resistances to the unknown resistance based on the lengths of wire sections.</p> Signup and view all the answers

In measuring resistivity using a metre bridge, what critical information must be accounted for regarding the resistors and lengths?

<p>The resistances must be in standard units, and the lengths must be in the same unit to accurately apply the formula $\frac{R_1}{R_2} = \frac{l_1}{l_2}$ for calculation.</p> Signup and view all the answers

Describe the process of measuring the diameter of a wire using a micrometer.

<p>To measure the diameter, first determine the zero error, then position the micrometer’s jaws around the wire and tighten until a click is heard. Finally, read the measurement on the scale, accounting for any observed zero error.</p> Signup and view all the answers

What are the steps involved in determining the resistivity of a wire using gathered data from a micrometer and ohmmeter?

<p>First, measure the wire's diameter and note the lead resistance. Then, measure the total resistance and length of the wire, and apply the formula $\rho = \frac{R \pi d^2}{4l}$ to find the resistivity.</p> Signup and view all the answers

How does temperature influence the resistance of a metallic conductor, and what is observed graphically from the experiments?

<p>As temperature increases, the resistance of a metallic conductor typically rises due to increased atomic vibrations. Graphically, this shows a straight line indicating a linear relationship between resistance and temperature.</p> Signup and view all the answers

What apparatus is essential for measuring the resistance of Nichrome wire, and why are each of these components necessary?

<p>Essential apparatus includes nichrome wire, a micrometer, an ohmmeter, leads with crocodile clips, and a metre stick. Each component is necessary for accurately measuring resistance, diameter, and lengths involved in calculations.</p> Signup and view all the answers

Flashcards

Angle (θ) in radians

Arc length (s) divided by radius (r).

Angular velocity (ω)

Angle change per unit time.

Linear velocity (v)

Speed perpendicular to radius.

Radian (rad)

SI unit for angle, 2π rad = 360°

Signup and view all the flashcards

Periodic time (T)

Time for one full cycle/oscillation.

Signup and view all the flashcards

Orbital period (T)

Time for one orbit.

Signup and view all the flashcards

Centripetal acceleration

Acceleration towards the center.

Signup and view all the flashcards

Centripetal force

Force towards the center to maintain circular motion.

Signup and view all the flashcards

Newton's Universal Law of Gravitation

Force between masses is proportional to product of masses and inversely proportional to square of distance.

Signup and view all the flashcards

Gravitational constant (G)

Constant in Newton's Law of Gravitation (6.7 x 10⁻¹¹ N m² kg⁻²)

Signup and view all the flashcards

Geostationary Satellite

Satellite in fixed position relative to Earth, matching Earth's rotation.

Signup and view all the flashcards

Weightlessness

Apparent lack of weight due to falling with the same rate as spacecraft.

Signup and view all the flashcards

s=θr

Arc Length equals angle in radians times the radius

Signup and view all the flashcards

v = ωr

Linear velocity equals angular velocity times radius.

Signup and view all the flashcards

T² = (4π² R³)/GM

Relationship between the period squared, radius cubed, mass and gravitational constant

Signup and view all the flashcards

Centripetal acceleration (unit)

m s⁻²

Signup and view all the flashcards

Centripetal force (unit)

N

Signup and view all the flashcards

Angular velocity unit

rad s⁻¹

Signup and view all the flashcards

Linear velocity unit

m s⁻¹

Signup and view all the flashcards

Resistance

The opposition a material offers to the flow of electric current. It is measured in ohms (Ω).

Signup and view all the flashcards

Ohm's Law

The relationship between voltage, current, and resistance: Voltage (V) equals current (I) multiplied by resistance (R). V = IR

Signup and view all the flashcards

Resistivity

A material's inherent ability to oppose electric current. It is measured in ohm-meters (Ω·m).

Signup and view all the flashcards

Resistor

A component designed to provide specific resistance in an electric circuit. It converts electrical energy into other forms, often heat.

Signup and view all the flashcards

Variable Resistor

A resistor whose resistance can be adjusted, typically using a slider or knob. Common types include potentiometers and rheostats.

Signup and view all the flashcards

Resistivity (ρ)

A material's resistance to electrical current flow, calculated as the resistance (R) multiplied by the cross-sectional area (A) and divided by the length (l): ρ = R*A/l. Measured in ohm meters (Ω m).

Signup and view all the flashcards

What does an ohmmeter measure?

An ohmmeter measures the resistance of a component. It is an instrument used to determine how much a component opposes the flow of electrical current.

Signup and view all the flashcards

Power (P)

The rate at which energy is produced or consumed per unit of time. Measured in watts (W). P = VI, where V is voltage and I is current.

Signup and view all the flashcards

Joule's Law

Defines the heat generated by an electrical current flowing through a resistor. W = I²Rt, where W is the heat energy, I is the current, R is the resistance, and t is time.

Signup and view all the flashcards

Series Circuit

A circuit where the components are connected in a single, continuous path. The current is the same at every point in the circuit.

Signup and view all the flashcards

Resistors in Series

Resistors connected end-to-end, forming a single path for current flow. The total resistance is the sum of individual resistances.

Signup and view all the flashcards

Resistors in Parallel

Resistors connected side-by-side, providing multiple paths for current flow. The total resistance is less than the smallest individual resistance.

Signup and view all the flashcards

Voltage Drop

The decrease in electrical potential energy as current moves through a resistor or component in a circuit.

Signup and view all the flashcards

Potential Divider

A circuit configuration that divides an input voltage across multiple resistors, creating a variable voltage output based on resistance ratios.

Signup and view all the flashcards

Potentiometer

A three-terminal resistor with a sliding contact, allowing for adjustable voltage division. It acts as a variable voltage divider.

Signup and view all the flashcards

Digital Controls vs. Potentiometers

Digital controls have replaced potentiometers in many consumer electronics due to their precision and ease of programming. However, potentiometers are still used for audio adjustments due to their analog nature.

Signup and view all the flashcards

Charge carriers in metals

Electrons are the charge carriers in metals. They flow from the negative terminal to the positive terminal, creating electrical current.

Signup and view all the flashcards

Effect of temperature on metallic resistance

As temperature increases, the resistance of a metallic conductor also increases. This is because the electrons collide with the vibrating atoms more frequently, hindering their flow.

Signup and view all the flashcards

Ohmic vs. Non-ohmic behavior

Ohmic behavior occurs when the current is directly proportional to voltage, resulting in a straight line on a graph. Non-ohmic behavior, like in a filament bulb, shows resistance increasing with temperature, causing a curved graph.

Signup and view all the flashcards

Charge carriers in ionic solutions

Ions are the charge carriers in ionic solutions. They are atoms or molecules with a net electric charge, moving under the influence of an electric field.

Signup and view all the flashcards

Conductivity and concentration

The conductivity of an ionic solution directly correlates with its concentration: More ions means better conductivity.

Signup and view all the flashcards

Active and inactive electrodes

Active electrodes participate in chemical reactions during electrolysis, changing their composition. Inactive electrodes provide a conductive path but don't change chemically.

Signup and view all the flashcards

Graph (b) for inactive electrodes

Graph (b) illustrates inactive electrodes where no current flows until a specific voltage is reached. This is due to a back emf generated by the voltameter.

Signup and view all the flashcards

Conduction in gases

Gases conduct electricity through the movement of ions and electrons. The process is influenced by pressure and voltage.

Signup and view all the flashcards

Wheatstone Bridge

A circuit used to measure an unknown resistance (R2) by balancing a known resistance (R1) with a variable resistance (R2) on a meter bridge. The ratio of resistances equals the ratio of lengths of the meter bridge wire.

Signup and view all the flashcards

How to Calculate Unknown Resistance

In a Wheatstone Bridge, the unknown resistance (R2) is calculated using the formula: R1/R2 = l1/l2, where R1 is a known resistance, l1 and l2 are lengths of the meter bridge wire.

Signup and view all the flashcards

Micrometer

A precision instrument used to measure small diameters or widths with high accuracy using a Vernier scale that moves past a main scale.

Signup and view all the flashcards

Measuring with a Micrometer

  1. Read Zero Error: Identify any offset when the jaws are closed. 2. Position Jaws: Clamp the object between the anvil and spindle. 3. Tighten Jaws: Rotate the ratchet until a click is heard. 4. Read & Correct: Combine main scale and Vernier scale readings and subtract zero error for the accurate measurement.
Signup and view all the flashcards

Resistivity of a Wire

The inherent ability of a material to oppose electrical current flow. Resistivity (ρ) can be calculated using the formula: ρ = Rπd²/4l, where R is the resistance, d is the diameter, and l is the length of the wire.

Signup and view all the flashcards

Measuring Resistance of Nichrome Wire

  1. Measure Diameter: Use a micrometer to determine the wire's diameter at different points. 2. Measure Length: Use a meter stick to measure the distance between crocodile clips. 3. Measure Total Resistance: Use an ohmmeter to measure the combined resistance of the wire and leads. 4. Subtract Lead Resistance: Find the wire's resistance by subtracting the resistance of the leads.
Signup and view all the flashcards

How does pressure affect gas conduction?

Lower pressure enhances conduction by decreasing resistance. This is because there are fewer gas molecules to obstruct the flow of charged particles.

Signup and view all the flashcards

What happens in a discharge tube when voltage increases beyond a certain point?

At high voltage, the energy of ions and electrons increases, leading to more frequent collisions with gas atoms. This process excites the atoms, causing them to emit light when they return to their ground state.

Signup and view all the flashcards

What is plasma?

Plasma is a partially ionized gas composed of ions and free electrons. It is often considered the fourth state of matter due to its unique properties, including electrical conductivity and responsiveness to magnetic fields.

Signup and view all the flashcards

What makes sodium street lamps energy-efficient?

Sodium street lamps convert a high percentage of input energy into visible light, making them highly efficient.

Signup and view all the flashcards

Why are sodium lamps ideal for outdoor lighting?

Sodium lamps emit light primarily near the peak sensitivity of the human eye, making them ideal for outdoor applications like street and security lighting.

Signup and view all the flashcards

What happens in a cathode ray tube?

Electrons are emitted from the cathode through thermionic emission and are attracted to the anode. Current increases with voltage until a plateau is reached.

Signup and view all the flashcards

What factors affect the number of electrons available for conduction in a vacuum?

The number of electrons available for conduction depends on the cathode's temperature and material.

Signup and view all the flashcards

What happens at point A on the current-voltage graph for a cathode ray tube?

At point A, all available electrons are used for conduction, so the current doesn’t increase further. Increasing the cathode temperature is necessary to raise the current.

Signup and view all the flashcards

How is light emitted from vapor?

When atoms in vapor are excited by energy, their electrons move to higher energy levels. As they return to their original levels, they release photons, causing light emission.

Signup and view all the flashcards

What does a Wheatstone bridge measure?

A Wheatstone bridge measures resistance by ensuring a constant potential difference between two points (A and D) while using a galvanometer to detect any current flow.

Signup and view all the flashcards

Study Notes

Angle and Angular Quantity

  • Angle (θ) in radians is calculated as the arc length (s) divided by the radius (r).
  • SI unit for angle is radian (rad), with 2π radians equating to 360 degrees.
  • Angular velocity (ω) is the measure of angle change per unit time, defined as a vector quantity with units of radians per second (rad s⁻¹).
  • Linear velocity (v) is speed in the direction perpendicular to the radius, a vector quantity with units of meters per second (m s⁻¹).

Relationships Between Angular and Linear Quantities

  • Expression of angle in radians: θ = s/r implies s = θr.
  • Linear velocity can be expressed as v = s/t, therefore v = θr/t.
  • For angular velocity, ω = θ/t, leading to the relation v = ωr.

Periodic Motion

  • Periodic time (T) represents the time for a full cycle or oscillation.
  • Orbital period (T) is the time taken for one complete orbit of an object around another.
  • Centripetal acceleration is directed toward the center during uniform circular motion, measured in meters per second squared (m s⁻²).

Forces in Circular Motion

  • Objects moving at constant speed in a circle are accelerating due to continuous direction change.
  • Centripetal force, required to maintain circular motion, is directed inward and measured in newtons (N).

Newton's Universal Law of Gravitation

  • The gravitational force between two point masses is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
  • Gravitational constant (G) is valued at 6.7 × 10⁻¹¹ N m² kg⁻².

Sample Calculation (Earth's Mass)

  • For the Moon's orbital speed (v = 1023 m s⁻¹) and radius (r = 3.8 × 10⁸ m), use:
    • GMm/d² = mv²/r to derive Earth's mass (M).
    • Result for Earth's mass: approximately 6 × 10²⁴ kg.

Weightlessness in Orbit

  • Astronauts appear weightless as they and their spacecraft fall at the same rate due to gravitational pull.

Relationship of Period, Mass, and Radius

  • From Newton’s 2nd Law: F_gravitational = F_centripetal results in:
    • Equation GM/R² = (4π² R)/T², linking gravitational mass, radius, and period.
    • Reorganizing gives T² = (4π² R³)/GM.

Sample Calculation (Moon's Orbit Radius)

  • Given the Moon's orbital period of 27 days, use:
    • T² = (4π² R³)/GM to find average radius (R).
    • Result for Moon's average orbit radius: approximately 3.8 × 10⁸ m.

Geostationary Satellites

  • Positioned at a height of about 36,000 km, geostationary satellites maintain a fixed position relative to Earth by matching Earth's rotation speed.
  • They enable consistent communication and weather observation.
  • Despite accelerating toward Earth (0.57 m s⁻²), the horizontal velocity (approximately 3.9 km s⁻¹) allows continuous circular motion without falling.

Angle and Angular Quantity

  • Angle (θ) in radians is calculated as the arc length (s) divided by the radius (r).
  • SI unit for angle is radian (rad), with 2π radians equating to 360 degrees.
  • Angular velocity (ω) is the measure of angle change per unit time, defined as a vector quantity with units of radians per second (rad s⁻¹).
  • Linear velocity (v) is speed in the direction perpendicular to the radius, a vector quantity with units of meters per second (m s⁻¹).

Relationships Between Angular and Linear Quantities

  • Expression of angle in radians: θ = s/r implies s = θr.
  • Linear velocity can be expressed as v = s/t, therefore v = θr/t.
  • For angular velocity, ω = θ/t, leading to the relation v = ωr.

Periodic Motion

  • Periodic time (T) represents the time for a full cycle or oscillation.
  • Orbital period (T) is the time taken for one complete orbit of an object around another.
  • Centripetal acceleration is directed toward the center during uniform circular motion, measured in meters per second squared (m s⁻²).

Forces in Circular Motion

  • Objects moving at constant speed in a circle are accelerating due to continuous direction change.
  • Centripetal force, required to maintain circular motion, is directed inward and measured in newtons (N).

Newton's Universal Law of Gravitation

  • The gravitational force between two point masses is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
  • Gravitational constant (G) is valued at 6.7 × 10⁻¹¹ N m² kg⁻².

Sample Calculation (Earth's Mass)

  • For the Moon's orbital speed (v = 1023 m s⁻¹) and radius (r = 3.8 × 10⁸ m), use:
    • GMm/d² = mv²/r to derive Earth's mass (M).
    • Result for Earth's mass: approximately 6 × 10²⁴ kg.

Weightlessness in Orbit

  • Astronauts appear weightless as they and their spacecraft fall at the same rate due to gravitational pull.

Relationship of Period, Mass, and Radius

  • From Newton’s 2nd Law: F_gravitational = F_centripetal results in:
    • Equation GM/R² = (4π² R)/T², linking gravitational mass, radius, and period.
    • Reorganizing gives T² = (4π² R³)/GM.

Sample Calculation (Moon's Orbit Radius)

  • Given the Moon's orbital period of 27 days, use:
    • T² = (4π² R³)/GM to find average radius (R).
    • Result for Moon's average orbit radius: approximately 3.8 × 10⁸ m.

Geostationary Satellites

  • Positioned at a height of about 36,000 km, geostationary satellites maintain a fixed position relative to Earth by matching Earth's rotation speed.
  • They enable consistent communication and weather observation.
  • Despite accelerating toward Earth (0.57 m s⁻²), the horizontal velocity (approximately 3.9 km s⁻¹) allows continuous circular motion without falling.

Angle and Angular Quantity

  • Angle (θ) in radians is calculated as the arc length (s) divided by the radius (r).
  • SI unit for angle is radian (rad), with 2π radians equating to 360 degrees.
  • Angular velocity (ω) is the measure of angle change per unit time, defined as a vector quantity with units of radians per second (rad s⁻¹).
  • Linear velocity (v) is speed in the direction perpendicular to the radius, a vector quantity with units of meters per second (m s⁻¹).

Relationships Between Angular and Linear Quantities

  • Expression of angle in radians: θ = s/r implies s = θr.
  • Linear velocity can be expressed as v = s/t, therefore v = θr/t.
  • For angular velocity, ω = θ/t, leading to the relation v = ωr.

Periodic Motion

  • Periodic time (T) represents the time for a full cycle or oscillation.
  • Orbital period (T) is the time taken for one complete orbit of an object around another.
  • Centripetal acceleration is directed toward the center during uniform circular motion, measured in meters per second squared (m s⁻²).

Forces in Circular Motion

  • Objects moving at constant speed in a circle are accelerating due to continuous direction change.
  • Centripetal force, required to maintain circular motion, is directed inward and measured in newtons (N).

Newton's Universal Law of Gravitation

  • The gravitational force between two point masses is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
  • Gravitational constant (G) is valued at 6.7 × 10⁻¹¹ N m² kg⁻².

Sample Calculation (Earth's Mass)

  • For the Moon's orbital speed (v = 1023 m s⁻¹) and radius (r = 3.8 × 10⁸ m), use:
    • GMm/d² = mv²/r to derive Earth's mass (M).
    • Result for Earth's mass: approximately 6 × 10²⁴ kg.

Weightlessness in Orbit

  • Astronauts appear weightless as they and their spacecraft fall at the same rate due to gravitational pull.

Relationship of Period, Mass, and Radius

  • From Newton’s 2nd Law: F_gravitational = F_centripetal results in:
    • Equation GM/R² = (4π² R)/T², linking gravitational mass, radius, and period.
    • Reorganizing gives T² = (4π² R³)/GM.

Sample Calculation (Moon's Orbit Radius)

  • Given the Moon's orbital period of 27 days, use:
    • T² = (4π² R³)/GM to find average radius (R).
    • Result for Moon's average orbit radius: approximately 3.8 × 10⁸ m.

Geostationary Satellites

  • Positioned at a height of about 36,000 km, geostationary satellites maintain a fixed position relative to Earth by matching Earth's rotation speed.
  • They enable consistent communication and weather observation.
  • Despite accelerating toward Earth (0.57 m s⁻²), the horizontal velocity (approximately 3.9 km s⁻¹) allows continuous circular motion without falling.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Description

This quiz covers essential concepts in physics related to angles, angular velocity, and linear velocity. Explore the definitions, measurements, and units associated with these fundamental quantities. Perfect for reinforcing your understanding of these topics in physics.

More Like This

Angular Speed: Concepts and Formulas
6 questions

Angular Speed: Concepts and Formulas

IntelligentCosine avatar
IntelligentCosine
Physics: Angular and Linear Velocity
10 questions

Physics: Angular and Linear Velocity

RestfulMotif avatar
RestfulMotif
Angular Velocity and Linear Velocity Concepts
5 questions

Angular Velocity and Linear Velocity Concepts

LeanMemphis835 avatar
LeanMemphis835
Physique Chapitre 11
42 questions

Physique Chapitre 11

ComplimentaryChiasmus2864 avatar
ComplimentaryChiasmus2864
Use Quizgecko on...
Browser
Open
Browser
Browser