Question

find the momentum of a body of mass 100 gram having a kinetic energy of 20 Joule

Answer 1

K=(1/2)*mv^2=20j
20= (1/2)*(0.1)v^2
V^2=400
V=20
P=mv= 0.1*20=2
P = 2 g*m/s

Answer 2

Hey there!
We know that Relationship between linear momentum and kinetic energy is

K = p^2/2m.

Given mass of body (m) = 100 g =0.1 kg

Kinetic energy( K) =20 J.

Now,

K = p^2/2m.

20 = p^2/2(0.1)

20*0.2 = p^2

p ^2 =4

p = 2

Therefore, Momentum of body is 2 kg m /s.

It can be obtained in other ways also :-

K=(mv ^2) /2


20 = m v^2 /2

20=0.1/2 v ^2

v^2 = 400

v =20 m/s

We know that,
Momentum P=mv

P =0.1 * 20


P = 2 kg m/s