Question

A ball of mass 5 kg moving with speed 8 metre per second collides head on with another stationary A ball of mass 15 kg if collision is perfectly inelastic the loss in kinetic energy is

Answer 1

Answer:

Here,

m1 = 5kg

u1 = 8m/s

m2 = 15kg

u2 = 0

According to law of conservation of momentum,

m1u1 + m2u2 = (m1+m2)v

=> 5×8 + 15×0 = (5+15)v

=> v = 2m/s

Now initial kinetic energy= 1/2m1u1^2 + 1/2m2u2^2

= 1/2×5×(8^2) + 1/2×15×0^2

= 160J

Final kinetic energy= 1/2(m1+m2)v^2

= 1/2×(5+15)×2^2 = 40J

Hence, Change in KE = 160-40 = 120J