Question

A particle is moving in translatory motion if momentum of the particle decreases by 10% kinetic energy will decrease by ​

Answer 1

if momentum decrease by 10 % then velocity also decreases by 10%

v is initial velocity ,then 0.1is decreased velocity.

final velocity= v-0.1v =0.9v

decreased KE= 1/2 m(0.9)² = 0.81

the kinetic energy will decrease by 1-0.81=0.19 KE

Answer 2

Answer: The correct answer is 19 percent.

Explanation:

It is given in the problem that a particle is moving in translatory motion if momentum of the particle decreases by 10%.

If there is 10 percent decrease in momentum then there is 10 percent decrease in velocity.

The velocity of the particle becomes as;

v'=v- 0.1v

v'= 0.9 v

The expression for the kinetic energy is as follows;

$KE= \frac{1}{2} mv'^{2}$

Here, m is the mass and v is the velocity.

Calculate the kinetic energy of particle when the momentum decreases by 10 percent.

Put v'= 0.9v.

$KE'= \frac{1}{2} m(0.9v)^{2}$

$KE'=0.81 KE$

Calculate the change in kinetic energy.

Change in kinetic energy= KE- 0.81KE

Change in kinetic energy= 0.19KE

Change in kinetic energy= 19 percent

Therefore, the kinetic energy will decrease by 19 percent.