Physics Kinematics and Forces Quiz
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Questions and Answers

What is the primary reason physicists emphasize the use of units?

  • To promote the use of the SI system exclusively.
  • To make comparisons between different physical quantities easier.
  • To ensure clarity and precision in measurements. (correct)
  • To simplify calculations involving numbers.

    • Which of these is NOT a fundamental quantity in physics?

  • Length
  • Mass
  • Electric Charge (correct)
  • Time

    • What does the ratio of length to time represent in physics?

  • Acceleration
  • Velocity (correct)
  • Distance
  • Momentum

    • What is typically the base unit of length in the SI system?

    <p>Meter</p> Signup and view all the answers

    How can other units, like the newton, be expressed?

    <p>As a combination of base SI units.</p> Signup and view all the answers

    Which system is primarily used in scientific measurements?

    <p>SI System</p> Signup and view all the answers

    What ensures that measurements of physical quantities are consistent?

    <p>Employing a system of units.</p> Signup and view all the answers

    What is the SI unit for electrical current?

    <p>Ampere</p> Signup and view all the answers

    What are the two major areas of medical physics?

    <p>Physics of physiology and clinical medical physics</p> Signup and view all the answers

    Which topic is covered in the first week of the MED 101 course?

    <p>Introduction, motion and statics of the body</p> Signup and view all the answers

    What is the distinction between average and instantaneous velocity?

    <p>Average velocity measures overall displacement, whereas instantaneous velocity measures speed at a specific time.</p> Signup and view all the answers

    In the context of kinematics, which of the following best defines displacement?

    <p>An object's overall change in position from start to end</p> Signup and view all the answers

    Which of the following statements is true regarding accuracy and uncertainty in measurements?

    <p>Uncertainty quantifies how close a measurement is to the true value.</p> Signup and view all the answers

    What aspect of the body's physics is investigated in Week 4 of the MED 101 course?

    <p>Thermodynamics and its application in treatment</p> Signup and view all the answers

    What is the main focus of clinical medical physics?

    <p>Using physics principles in medical diagnosis and treatment</p> Signup and view all the answers

    What role does mathematics play in the study of physics according to the content provided?

    <p>While important, physics also incorporates theoretical concepts beyond mathematics.</p> Signup and view all the answers

    What is the definition of displacement?

    <p>The distance traveled with a direction associated.</p> Signup and view all the answers

    When is an object's velocity considered to be accelerating?

    <p>When its speed or direction changes.</p> Signup and view all the answers

    What is the SI unit for average velocity?

    <p>Meter per second (m/s)</p> Signup and view all the answers

    If a particle moves from position x1 = 5m to x2 = 200m, and then back to x1 = 5m, what is the total displacement?

    <p>0m</p> Signup and view all the answers

    Average speed differs from average velocity because average speed:

    <p>Is the total distance covered, independent of direction.</p> Signup and view all the answers

    What is the formula for average acceleration?

    <p>$\alpha = \frac{\Delta v}{\Delta t}$</p> Signup and view all the answers

    What is the value of acceleration due to gravity, denoted by g?

    <p>$9.8 m/s²$</p> Signup and view all the answers

    Which statement about distance is correct?

    <p>Distance ignores the direction of travel.</p> Signup and view all the answers

    What defines a force in physics?

    <p>A measurable influence that causes a change in the motion of an object.</p> Signup and view all the answers

    According to Newton's first law, what will happen to an object at rest?

    <p>It will remain at rest unless acted upon by an external force.</p> Signup and view all the answers

    The relationship between force, mass, and acceleration is expressed by which equation?

    <p>$F = m imes a$</p> Signup and view all the answers

    What does the symbol 'g' represent in physics?

    <p>Acceleration due to gravity.</p> Signup and view all the answers

    What is the SI unit of force?

    <p>Newton.</p> Signup and view all the answers

    When an object falls under the influence of gravity, the force acting on it is known as what?

    <p>Weight.</p> Signup and view all the answers

    What is true about the weight of an object?

    <p>Weight is a force and not a mass.</p> Signup and view all the answers

    Which statement is correct about the force of gravity?

    <p>Gravity always pulls objects towards the Earth regardless of their mass.</p> Signup and view all the answers

    What must be true for a system to be in static equilibrium?

    <p>The net force and net torque are both zero.</p> Signup and view all the answers

    Which of the following describes a stable equilibrium?

    <p>An object returns to equilibrium after a small displacement.</p> Signup and view all the answers

    Where must the center of mass be for maximum stability whilst standing?

    <p>Above the area spanned by the feet.</p> Signup and view all the answers

    What indicates that an object is in an unstable equilibrium?

    <p>Torques cannot balance after a displacement.</p> Signup and view all the answers

    Which factor contributes to the stability of an object?

    <p>A narrower top with a broader base.</p> Signup and view all the answers

    What effect does leaning away from the center of the support base have on stability?

    <p>It can lead to instability and potential toppling.</p> Signup and view all the answers

    What happens to the torques about the feet when the center of mass is directly above it?

    <p>The torques cancel each other out.</p> Signup and view all the answers

    What best defines torque in a physical context?

    <p>The turning effect of a force about a pivot.</p> Signup and view all the answers

    What does the prefix 'peri-' signify in medical terminology?

    <p>Around</p> Signup and view all the answers

    Which of the following describes the suffix '-itis' in medical terms?

    <p>Inflammation</p> Signup and view all the answers

    In the context of medical terminology, the term 'phonocardiography' combines which elements?

    <p>Sound and heart recording</p> Signup and view all the answers

    Which prefix indicates a factor of $10^6$?

    <p>Mega-</p> Signup and view all the answers

    When converting units, what is the method called that uses a conversion factor equal to unity?

    <p>Chain-link conversion</p> Signup and view all the answers

    What is the SI unit of force?

    <p>Newton</p> Signup and view all the answers

    According to Newton's second law, what is the relationship between force and acceleration?

    <p>Force is proportional to mass times acceleration.</p> Signup and view all the answers

    What does the symbol 'g' represent in physics?

    <p>Acceleration due to gravity</p> Signup and view all the answers

    What is the formula for calculating the weight of an object?

    <p>W = m * g</p> Signup and view all the answers

    What happens to an object if no external force acts on it according to Newton's first law?

    <p>It will remain at rest or move at constant velocity.</p> Signup and view all the answers

    What is the primary difference between accuracy and precision in measurements?

    <p>Accuracy is related to how close a measurement is to a standard, while precision relates to the repeatability of the measurement.</p> Signup and view all the answers

    When introducing conversion factors in unit conversions, what must be ensured?

    <p>That the unwanted units cancel appropriately during the conversion.</p> Signup and view all the answers

    What does uncertainty in a measurement represent?

    <p>A numeric measure of confidence in a measurement or result.</p> Signup and view all the answers

    What should be the relationship between measured values and accepted standards for accuracy?

    <p>Measured values should be close to accepted values without necessarily matching.</p> Signup and view all the answers

    In scientific measurements, what is the effect of introducing a conversion factor incorrectly?

    <p>It may lead to a calculation that does not accurately reflect the intended conversion.</p> Signup and view all the answers

    What is the significance of significant figures in scientific measurements?

    <p>They represent the precision limit at which a measurement can be reported.</p> Signup and view all the answers

    How is precision defined in measurements?

    <p>The variability of measurements over multiple trials.</p> Signup and view all the answers

    Which statement is correct about leading zeros in significant figures?

    <p>Leading zeros are never significant.</p> Signup and view all the answers

    What happens when you add numbers with different decimal places?

    <p>The answer must be rounded to the least number of decimal places.</p> Signup and view all the answers

    How are trailing zeros treated in significant figures?

    <p>Trailing zeros are significant only when the decimal point is specified.</p> Signup and view all the answers

    If a number is 45.2, to how many significant figures should it be rounded if required?

    <p>3 significant figures.</p> Signup and view all the answers

    What does position refer to in a kinematics context?

    <p>The location of an object relative to a reference point.</p> Signup and view all the answers

    What is the significance of an origin point in measuring position?

    <p>It serves as a reference point for other measurements.</p> Signup and view all the answers

    How many significant figures are in the number 300.0?

    <p>4 significant figures.</p> Signup and view all the answers

    Which of the following correctly defines a large number in scientific notation?

    <p>A number expressed in the form of $a \times 10^n$, where $a$ is between 1 and 10.</p> Signup and view all the answers

    When is an object's velocity considered to be accelerating?

    <p>When the object changes its speed or direction.</p> Signup and view all the answers

    Which best describes imbedded zeros in a number?

    <p>Imbedded zeros are always significant.</p> Signup and view all the answers

    Study Notes

    Units

    • Physics deals with quantities measured with units, such as meters for length and seconds for time.
    • Units are carefully defined amounts of a quantity.
    • Physics uses the International System of Units (SI), based on the metric system and using base units like meters, seconds, and kilograms.
    • Common derived units can be expressed as combinations of base SI units, like speed being meters per second (m/s).

    Kinematics

    • Kinematics studies the motion of bodies.
    • Distance represents the total length of the path traveled.
    • Displacement is the change in position with direction, a vector quantity.
    • Average velocity is the displacement divided by the elapsed time.
    • Average speed is the total distance traveled divided by the time.
    • Acceleration is the change in velocity over time.

    Forces

    • Force is a measurable influence that causes a change in the motion of an object.
    • Newton's first law states that an object at rest or moving at constant velocity remains that way unless acted on by an external force.
    • Newton's second law describes the relation between force, mass, and acceleration: 𝐹 = 𝑚𝛼.
    • Newton's third law states that for every action, there is an equal and opposite reaction force.
    • Weight is the force due to gravity acting on an object, calculated as W = mg, where g is the acceleration due to gravity (9.81 m/s²).

    Normal, Friction, and Tension Forces

    • Normal force is the force exerted by a surface perpendicular to the object in contact.
    • Friction opposes motion between two surfaces in contact.
    • Tension force occurs in ropes and strings when they are pulled taut.

    Torque

    • Torque represents the tendency of a force to rotate an object around an axis, fulcrum, or pivot point.
    • Torque can be thought of as a twist.

    Equilibrium

    • A system is in equilibrium when the net force and net torque on it are zero.
    • Static equilibrium occurs when the system is in equilibrium and stationary.
    • Stable equilibrium implies the system returns to its equilibrium position after a small displacement.
    • Unstable equilibrium means the system does not return to its equilibrium position after a small displacement.

    Standing Stability

    • Stability during standing is essential for maintaining balance.
    • For overall stability, the center of mass must be over the area spanned by the feet.
    • If the center of mass is outside the support base, the system is unstable and may topple over.
    • The line of gravity passing through the center of the support base signifies stable equilibrium.
    • We are most stable when the line of gravity falls closer to the center of the support base.

    Medical Terminology

    • The term "pericarditis" refers to inflammation surrounding the heart.
    • It is constructed from the prefix "peri-" meaning "surrounding," the root "cardi" meaning "heart," and the suffix "-itis" meaning "inflammation."
    • The term "phonocardiography" refers to the graphic recording of heart sounds.
    • It is constructed from the prefix "phono" meaning "sound," the root "cardi" meaning "heart," and the suffix "graph" meaning "write."

    Prefixes and Units

    • Prefixes are used to represent quantities in powers of 10.
    • Common prefixes include: pico-, nano-, micro-, milli-, centi-, kilo-, mega-, giga-, tera-.
    • Prefixes are used to express very large or very small numbers more conveniently.
    • For example, a nanosecond is one billionth of a second (1 x 10^-9 seconds).

    Changing Units

    • Changing units involves multiplying the original measurement by a conversion factor.
    • A conversion factor is a ratio of units equal to unity.
    • For example, to convert minutes to seconds, multiply by (60 seconds/ 1 minute).

    Accuracy, Uncertainty, and Significant Figures

    • Accuracy refers to how close a measurement is to the true value.
    • Precision refers to the reproducibility of a measurement.
    • Uncertainty is a numeric measure of confidence in a measurement, with lower uncertainty indicating greater confidence.
    • Leading zeros are never significant.
    • Imbedded zeros are always significant.
    • Trailing zeros are significant only if the decimal point is specified.

    Forces and Newton's Laws

    • Force is a measurable influence that causes a change in an object's motion.
    • Newton's first law states that an object at rest or in motion will remain in that state unless acted upon by an external force.
    • Newton's second law states that the acceleration of an object is directly proportional to the force applied and inversely proportional to its mass (F = ma).
    • The SI unit of force is the Newton (N).
    • Weight is a force due to gravity and is expressed in Newtons.

    Equilibrium and Stability

    • A system is in equilibrium when the net force and net torque on the system are zero.
    • A system in static equilibrium is in equilibrium and stationary.
    • A system in stable equilibrium will return to equilibrium after a small displacement.
    • A system in unstable equilibrium will not return to its equilibrium state after a small displacement.
    • Stability during standing requires the center of mass to be over the area spanned by the feet.
    • When the line of gravity is near the center of the support base, an individual is most stable.
    • When leaning, the line of gravity may pass through the periphery of the base or even outside it, resulting in less stability.

    Torque

    • Torque is the tendency of a force to rotate an object about an axis, fulcrum, or pivot.
    • It can be thought of as a "twist."

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    Description

    Test your knowledge of kinematics and forces in physics. This quiz covers key concepts such as units of measurement, motion, and Newton's laws. Perfect for students looking to reinforce their understanding of these foundational topics.

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