Question

What is the velocity of mass of 100 g having K . E of 40 J ?

Answer 1

Mass, m = 100g = 0.1kg

Kinetic energy = (1/2)*mv^2 = 20J

mv^2 = 40

v^2= 40/0.1= 400

v = 20 m/s

Momentum = mv

= 0.1 * 20

= 2 kg m/s

Or

KE = P^2/ (2m)

P^2= 2m* KE= 2*0.1*20=4

P= 2 kg m/s