Q18 of 49 Page 11

Find the change in momentum of a body when its kinetic energy becomes four times the original value.

We know that

Kinetic Energy =


P = Momentum.


Ki = Initial Kinetic Energy


Pi = Initial Momentum


⇒


Kf = Final Kinetic Energy


Pf = Final Momentum


⇒


Given Kf = 4 Ki


⇒


⇒


⇒


Hence the Momentum of body will be doubled when the kinetic energy is increased four times.

More from this chapter

All 49 →
16

A boy of mass 50 kg runs up a staircase of 45 steps in 9s. If the height of each step is 15 cm, find his power. (Take g = 10 ms-2)

 17

Find the energy possessed by an object of mass 10 kg when it is at a height of 6m above the ground. [g = 9.8 ms-1]

 19

Define kinetic energy and potential energy and give examples.

 20

In each of the following a Force F is acting on an object of mass m.



The direction of displacement is from west to east shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero.