Asked in PMC Practice Test 28 (2021) 2021

If momentum is increased by 20% then K.E. increase by :

Correct answer: A. 0.44

  • A. 0.44
  • B. 0.55
  • C. 0.66
  • D. 0.77

Explanation

If momentum is increased by 20%, then the kinetic energy increases by 44% or 0.44 The kinetic energy of an object is given by the equation KE = 1/2mv2, where KE is the kinetic energy, m is the mass of the object, and v is the velocity of the object. The momentum of an object is given by the equation p = mv, where p is the momentum, m is the mass of the object, and v is the velocity of the object. If the momentum is increased by 20%, then the new momentum is 1.2 times the old momentum. Therefore, p2 = 1.2p1. Using the equations for momentum and kinetic energy, we can derive the following equation: KE2 = 1/2m(v2)2 = 1/2m[(p2/m)2/m2] = 1/2(p22/m2). Substituting p2 = 1.2p1, we get KE2 = 1/2[(1.2p1)2/m2] = 1.44(1/2)(p12/m2) = 1.44KE1. Therefore, if momentum is increased by 20%, then the kinetic energy increases by 44%

Written and checked by , contributorLast updated
Report an error

The more specific you are, the faster it gets fixed. A source beats an opinion.

Prefer email? [email protected]

About Kinetic Energy

Kinetic energy is the energy of motion, given for a nonrelativistic object by K = ½mv², so it depends on mass and the square of speed. Questions connect kinetic energy with work through the work energy theorem, calculate changes in kinetic energy, and distinguish it from momentum and potential energy.

Practise Work and Energy

748 free Work and Energy MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Discussion

Stuck on an option, or know a faster way to get there? Ask or explain it here.

No comments yet. Be the first to explain this one.

Exams that ask Physics questions like this

Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

More Kinetic Energy questions