Asked in UHS MDCAT 2010 2010Moderate

If a force of 12 N acts on a car and changes its momentum from 36 kgm/sec to 60 kgm/sec, the time during which this change occurs will be

Correct answer: B. 2 sec

  • A. 24 sec
  • B. 2 sec
  • C. 12 sec
  • D. 8 sec

Explanation

To solve this problem, use the impulse-momentum theorem, which states that the impulse (force multiplied by time) is equal to the change in momentum. The formula is:F×t = mvf - mviSubstitute the given values: F = 12 N, mvf = 60 kgm/s, and mvi = 36 kgm/s.Therefore, t = (60 kgm/s - 36 kgm/s) / 12 N = 24 kgm/s / 12 N = 2 sec.This means the correct time interval is 2 seconds.Options 24 sec, 12 sec, and 8 sec are incorrect because they result from errors in dividing the change in momentum by the force.

Last updated

About Linear Momentum

Linear momentum is the vector product of mass and velocity, p = mv, and changes when a net external force acts. Work includes impulse as the change in momentum, conservation of momentum in isolated systems, collisions and explosions, and the distinction between elastic, inelastic and perfectly inelastic collisions.

Practise Force and Motion

1,416 free Force and Motion MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Exams that ask Physics questions like this

Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

Related questions