Question

The momentum of a bullet of mass 20 g fired from a gun is 10 kg.m/s. The kinetic energy of this bullet in kJ will be :

विकल्प

• 5

• 1.5

• 2.5

• 25

Answer 1

Mass of the bullet, (m), = 0.02 gm
Momentum of the bullet, (P) = 10 kg.m/s
The relation between momentum, mass and kinetic energy is as follows -
`K.E = 1/2 (P^2/m)`
So , 
`K.E = 1/2 ((10)^2/0.02)` J
= `100/0.04` J
= 2500 J
= 2.5 KJ
Therefore, the answer is - 2.5.