Question

23. The momentum of a bullet
of mass 20g fired from a gun is
10kgm/s. The kinetic energy of
this bullet in kg will be​

Answer 1

The mass of bullet is 20 g or 0.02 kg.

The momentum of the bullet is 10 kg⋅m/s

The kinetic energy of a body in terms of its momentum is given as:

KE=2mp2

KE=2×0.0210×10

2500 J= 2.5 kJ

The correct answer is c) 2.5

Answer 2

Answer:

Your ans

To calculate the kinetic energy of the bullet,with the numerical data mentioned in the question,we have to do following calculations:

According to the law of momentum:

P=MV

V=P/M

V=10/20

V=1/2

And, according to the law of kinetic energy:

KE=1/2MV²

KE=1/2×20×1/4

KE=2.5

So the kinetic energy of the bullet will be

Your Ans 2.5KJ