Physics · Science General

Collisions, Momentum and Kinetic Energy

385 Questions

Collisions, momentum, and kinetic energy questions analyze the principles of elastic and inelastic impacts. They require calculating mass, velocity, and conserved energy during physical interactions. These foundational physics topics are essential for most government engineering and general science examinations.

Elastic collisionsInelastic collisionsMomentum calculationKinetic energy principlesVelocity after impact

Collisions, Momentum and Kinetic Energy Questions

Multiple choice

When two balls of same temperature collide, which of the following remains conserved?

  1. Temperature

  2. Velocity

  3. Linear momentum

  4. Kinetic energy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Linear momentum is always conserved in any collision (elastic or inelastic) when no external forces act. Temperature remaining the same is a condition stated in the problem, not a conserved quantity. Velocity and kinetic energy are NOT conserved - in inelastic collisions, kinetic energy is lost to deformation/heat, and velocities of individual balls change.

Multiple choice

Momentum of a body is defined as

  1. rate of change of velocity

  2. mass x velocity

  3. mass x acceleration

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Momentum (p) is a vector quantity defined as the product of an object's mass and its velocity (p = mv). It represents the quantity of motion and is conserved in closed systems. Mass × acceleration is force, not momentum.

Multiple choice

The momentum of a body is increased by 25%. The kinetic energy is increased by about ______.

  1. 34%

  2. 56%

  3. 65%

  4. 5%

  5. 23%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Kinetic energy of body is K = p2/2m Where p is the momentum and m is the mass of a body respectively ... k proportional to p2 When the momentum of a body is increased by 25%, its momentum will become P' = p + (25/100)p = (125/100)p = (5/4)p ... k'/k = p' 2/p2 = (5/4)2 = 25/16 or k' = (25/16)k Percentage increase in the kinetic energy of the body = (k ' -k)/k = {(25/16)k - k}/k= (9/16) Χ 100 = 56%

Multiple choice

In which of the following cases is the maximum friction observed?

  1. A ball hits another ball rolling across the billiards' table.

  2. A boy dragging a mat on which another boy is seated.

  3. Holding a greasy tumbler.

  4. Playing carrom on a board that was sprinkled with powder.

  5. A boy doing roller skating.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The boy dragging the mat has to pull the weight of the other boy seated on it. So, there is more friction on the mat.

Multiple choice

The sum of the kinetic and potential energies of a freely falling body is

  1. constant at all points

  2. maximum in the beginning

  3. minimum in the beginning

  4. maximum in the middle of the path
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In free fall under gravity, potential energy decreases while kinetic energy increases, but their total remains constant (neglecting air resistance). This is the law of conservation of mechanical energy. The body's energy is continuously converting between potential and kinetic forms.

Multiple choice

If the momentum of a body is doubled, the kinetic energy

  1. is halved

  2. is unchanged

  3. is doubled

  4. increases 4 times

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Kinetic energy (KE) is related to momentum (p) by the formula KE = p^2 / (2m). If momentum is doubled (2p), the new kinetic energy becomes (2p)^2 / (2m) = 4 * (p^2 / 2m), which is 4 times the original.

Multiple choice

Kinetic energy of a body is

  1. vector

  2. scalar

  3. psuedo vector

  4. independent of velocity
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Any type of energy and workdone is a scalar quantity, hence correct answer is (2)

Multiple choice

Which of the following statements is true?

  1. Kinetic energy and momentum both are conserved in all types of motion.

  2. Momentum is conserved in elastic collision but not in inelastic collision.

  3. Total kinetic energy is not conserved but momentum is conserved in inelastic collision.

  4. All the above are correct.
Reveal answer Fill a bubble to check yourself
B Correct answer