Physics Chapter on Angle and Velocity

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

<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

<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

<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

<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

<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

<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

<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

<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

<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

<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

<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

<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

<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

<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

<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

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

<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

<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

<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

<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

<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

<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

<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

<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

<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

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

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

<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

<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

<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

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

<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

<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

<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

<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

<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

<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

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

<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

<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

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

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

<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

<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

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

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

<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

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

<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

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

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

<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

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

<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

<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

<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

<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

<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

<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

<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