College Physics Practice Questions
& Answers
Question 1 (Kinematics). A ball is thrown horizontally from a cliff with an initial speed of 10 m/s. Ignoring air
resistance, what happens to its horizontal velocity during the fall?
A. It increases steadily
B. It remains constant
C. It decreases steadily
D. It becomes zero at the peak
Correct Answer: B
Explanation: With no horizontal forces acting (ignoring air resistance), horizontal velocity remains constant
throughout projectile motion.
Question 2 (Kinematics). A car accelerates uniformly from rest to 20 m/s in 5 seconds. What is its acceleration?
A. 2 m/s²
B. 4 m/s²
C. 5 m/s²
D. 10 m/s²
Correct Answer: B
Explanation: Acceleration = Δv/Δt = 20/5 = 4 m/s².
Question 3 (Newton's Laws). A 5 kg box is pushed with a net force of 15 N. What is its acceleration?
A. 1 m/s²
B. 3 m/s²
C. 5 m/s²
D. 15 m/s²
Correct Answer: B
Explanation: By Newton's second law, a = F/m = 15/5 = 3 m/s².
Question 4 (Newton's Laws). According to Newton's third law, when a rocket expels gas downward, the rocket
experiences a force that is:
A. In the same direction as the gas
B. Equal in magnitude and opposite in direction to the force on the gas
C. Zero
D. Only felt by the gas
Correct Answer: B
Explanation: Newton's third law states every action has an equal and opposite reaction; the rocket is pushed
upward as gas is expelled downward.
Question 5 (Work & Energy). How much work is done lifting a 10 kg object 2 meters vertically at constant
velocity (g = 9.8 m/s²)?
A. 19.6 J
B. 98 J
C. 196 J
D. 20 J
Correct Answer: C
, Explanation: Work = mgh = 10 × 9.8 × 2 = 196 J.
Question 6 (Work & Energy). A spring with spring constant 200 N/m is compressed 0.1 m. What is the elastic
potential energy stored?
A. 1 J
B. 2 J
C. 10 J
D. 20 J
Correct Answer: A
Explanation: PE = ½kx² = ½ × 200 × (0.1)² = 1 J.
Question 7 (Momentum). Two objects of equal mass collide and stick together in a perfectly inelastic collision. If
one was moving at 6 m/s and the other at rest, what is their combined velocity after collision?
A. 6 m/s
B. 3 m/s
C. 0 m/s
D. 12 m/s
Correct Answer: B
Explanation: By conservation of momentum: m(6) + m(0) = 2m(v), so v = 3 m/s.
Question 8 (Momentum). Which statement correctly describes conservation of momentum in a closed system?
A. Momentum is conserved only in elastic collisions
B. Total momentum before and after a collision remains constant if no external forces act
C. Momentum is only conserved when kinetic energy is conserved
D. Momentum increases after every collision
Correct Answer: B
Explanation: Conservation of momentum applies to any collision (elastic or inelastic) as long as no external
net force acts on the system.
Question 9 (Rotation). A solid disk and a hoop of the same mass and radius roll down an incline without slipping.
Which reaches the bottom first?
A. The hoop, because it has greater moment of inertia
B. The disk, because it has a smaller moment of inertia and converts more energy to translational motion
C. They arrive at the same time regardless of shape
D. Neither moves without slipping
Correct Answer: B
Explanation: The disk has a smaller rotational moment of inertia (½mr² vs mr² for the hoop), so more of its
energy goes into translational motion, making it accelerate faster.
Question 10 (Rotation). What is the torque produced by a 20 N force applied perpendicular to a 0.5 m lever arm?
A. 5 N·m
B. 10 N·m
C. 20 N·m
D. 40 N·m
Correct Answer: B
Explanation: Torque = force × lever arm = 20 × 0.5 = 10 N·m.
Question 11 (Gravity). According to Newton's law of universal gravitation, if the distance between two masses is
doubled, the gravitational force between them:
& Answers
Question 1 (Kinematics). A ball is thrown horizontally from a cliff with an initial speed of 10 m/s. Ignoring air
resistance, what happens to its horizontal velocity during the fall?
A. It increases steadily
B. It remains constant
C. It decreases steadily
D. It becomes zero at the peak
Correct Answer: B
Explanation: With no horizontal forces acting (ignoring air resistance), horizontal velocity remains constant
throughout projectile motion.
Question 2 (Kinematics). A car accelerates uniformly from rest to 20 m/s in 5 seconds. What is its acceleration?
A. 2 m/s²
B. 4 m/s²
C. 5 m/s²
D. 10 m/s²
Correct Answer: B
Explanation: Acceleration = Δv/Δt = 20/5 = 4 m/s².
Question 3 (Newton's Laws). A 5 kg box is pushed with a net force of 15 N. What is its acceleration?
A. 1 m/s²
B. 3 m/s²
C. 5 m/s²
D. 15 m/s²
Correct Answer: B
Explanation: By Newton's second law, a = F/m = 15/5 = 3 m/s².
Question 4 (Newton's Laws). According to Newton's third law, when a rocket expels gas downward, the rocket
experiences a force that is:
A. In the same direction as the gas
B. Equal in magnitude and opposite in direction to the force on the gas
C. Zero
D. Only felt by the gas
Correct Answer: B
Explanation: Newton's third law states every action has an equal and opposite reaction; the rocket is pushed
upward as gas is expelled downward.
Question 5 (Work & Energy). How much work is done lifting a 10 kg object 2 meters vertically at constant
velocity (g = 9.8 m/s²)?
A. 19.6 J
B. 98 J
C. 196 J
D. 20 J
Correct Answer: C
, Explanation: Work = mgh = 10 × 9.8 × 2 = 196 J.
Question 6 (Work & Energy). A spring with spring constant 200 N/m is compressed 0.1 m. What is the elastic
potential energy stored?
A. 1 J
B. 2 J
C. 10 J
D. 20 J
Correct Answer: A
Explanation: PE = ½kx² = ½ × 200 × (0.1)² = 1 J.
Question 7 (Momentum). Two objects of equal mass collide and stick together in a perfectly inelastic collision. If
one was moving at 6 m/s and the other at rest, what is their combined velocity after collision?
A. 6 m/s
B. 3 m/s
C. 0 m/s
D. 12 m/s
Correct Answer: B
Explanation: By conservation of momentum: m(6) + m(0) = 2m(v), so v = 3 m/s.
Question 8 (Momentum). Which statement correctly describes conservation of momentum in a closed system?
A. Momentum is conserved only in elastic collisions
B. Total momentum before and after a collision remains constant if no external forces act
C. Momentum is only conserved when kinetic energy is conserved
D. Momentum increases after every collision
Correct Answer: B
Explanation: Conservation of momentum applies to any collision (elastic or inelastic) as long as no external
net force acts on the system.
Question 9 (Rotation). A solid disk and a hoop of the same mass and radius roll down an incline without slipping.
Which reaches the bottom first?
A. The hoop, because it has greater moment of inertia
B. The disk, because it has a smaller moment of inertia and converts more energy to translational motion
C. They arrive at the same time regardless of shape
D. Neither moves without slipping
Correct Answer: B
Explanation: The disk has a smaller rotational moment of inertia (½mr² vs mr² for the hoop), so more of its
energy goes into translational motion, making it accelerate faster.
Question 10 (Rotation). What is the torque produced by a 20 N force applied perpendicular to a 0.5 m lever arm?
A. 5 N·m
B. 10 N·m
C. 20 N·m
D. 40 N·m
Correct Answer: B
Explanation: Torque = force × lever arm = 20 × 0.5 = 10 N·m.
Question 11 (Gravity). According to Newton's law of universal gravitation, if the distance between two masses is
doubled, the gravitational force between them:
