BS Physics Fundamentals 1 — Questions and Answers
Question 1: According to Newton's second law, which equation correctly relates net force, mass, and acceleration?
- F = mv
- F = ma (Correct answer)
- F = m/a
- F = pa
Correct answer: F = ma
Newton's second law states that net force equals mass multiplied by acceleration (F = ma).
Question 2: In projectile motion, what primarily determines the horizontal range of a horizontally launched object (ignoring air resistance)?
- The initial vertical velocity
- The time the object is in the air (Correct answer)
- The gravitational acceleration alone
- The mass of the object
Correct answer: The time the object is in the air
Horizontal range equals horizontal velocity multiplied by time of flight, so the time in the air determines how far the object travels horizontally.
Question 3: The work-energy theorem states that the net work done on an object equals:
- The change in its potential energy
- The change in its kinetic energy (Correct answer)
- The product of force and time
- The total mechanical energy
Correct answer: The change in its kinetic energy
The work-energy theorem establishes that W_net = ΔKE, meaning net work causes a change in an object's kinetic energy.
Question 4: Two objects undergo a perfectly inelastic collision. Which quantity is conserved?
- Kinetic energy only
- Momentum only (Correct answer)
- Both momentum and kinetic energy
- Neither momentum nor kinetic energy
Correct answer: Momentum only
Momentum is conserved in all collisions, but kinetic energy is lost to heat and deformation in a perfectly inelastic collision.
Question 5: If the distance between two masses is doubled, Newton's law of universal gravitation predicts the gravitational force between them becomes:
- Four times stronger
- Twice as strong
- One-half as strong
- One-quarter as strong (Correct answer)
Correct answer: One-quarter as strong
Gravitational force is inversely proportional to the square of the distance (F ∝ 1/r²), so doubling the distance reduces the force by a factor of four.
Question 6: An object in uniform circular motion experiences centripetal acceleration directed:
- Tangent to the path in the direction of motion
- Away from the center of the circle
- Toward the center of the circle (Correct answer)
- Perpendicular to the plane of the circle
Correct answer: Toward the center of the circle
Centripetal acceleration always points toward the center of the circular path, providing the inward force that sustains circular motion.
Question 7: A wrench applies torque to a bolt. If the applied force is doubled and the lever arm is halved, how does the torque change?
- It doubles
- It remains the same (Correct answer)
- It is halved
- It quadruples
Correct answer: It remains the same
Torque = force × lever arm; doubling the force and halving the lever arm gives the same product (2F × r/2 = Fr), so torque is unchanged.
BS Physics Fundamentals 1
According to Newton's second law, which equation correctly relates net force, mass, and acceleration?