Force, Motion & Gravity MCQs with Answers

Why does a person falling on a soft cushion not get hurt?

• A.The cushion reduces the mass of the person
• B.The time taken for the body to come to rest is delayed due to the cushion effect
• C.The cushion increases the force of impact on the body
• D.The cushion absorbs all the kinetic energy instantly

A ball of mass m strikes a wall and rebounds with the same speed in the opposite direction. Taking the initial direction as positive, the change in the momentum of the ball is _?

• A.mv
• B.2mv
• C.-2mv
• D.0

A disc, a hoop and a sphere of same mass and radius are rolled down from a frictionless inclined plane. Which has greater speed of reaching the ground?

• A.Disc
• B.Hoop
• C.Sphere
• D.All reach with same speed

A body is in unstable equilibrium after a slight tilt if its center of gravity ?

• A.Remains above the point of contact
• B.Falls below the point of contact
• C.Shifts to the same horizontal level as the point of contact
• D.Moves away from the body entirely

A projectile is thrown with velocity 30 m/s at an angle of 45°. Find its range. (Take g = 9.8 m/s²)

• A.30 m
• B.45 m
• C.60 m
• D.92 m

The value of gravitational acceleration changes with altitude. What is the effect on it as altitude increases?

• A.Increases
• B.Decreases
• C.Remains constant
• D.First increases then decreases

Force is a _ quantity.

• A.Base
• B.Derived
• C.Fundamental
• D.Scalar

While launching a rocket of mass 2×10^4 kg, a force of 5×10^5 N is applied for 20s. Calculate the velocity attained by the rocket at the end of 20s?

• A.500 m/s
• B.250 m/s
• C.1000 m/s
• D.400 m/s

Which is the Newton's second law of motion?

• A.F = ma
• B.F = mv
• C.F = m/a
• D.F = 1/2 mv²

The momentum of a body changes by 5 kg m/s when a force F is applied for a time interval of 2 seconds. What is the magnitude of force F?

• A.10 N
• B.2.5 N
• C.0.4 N
• D.7 N