Question

a paricle of mass 5 kg strikes a body of mass 2.5kg at rest elastically.the 2.5 kg mass after collision movies with a kinetic energy of 5j.the kinetic energy of 5 kg mass before collision is

Answer 1

Answer:5.625

Explanation:

Given k.e of the mass 2.5 kg is 5j.

So,5=1/2×2.5×v^2.(here v is the final velocity of the mass 2.5kg)

Therfore v of 2.5 kg block is 2.

We know the formula that

Velocity of 2.5 kg object =2m1u1/m1+m2

So,2=2×5×u1/5+2.5

U1=3/2

So k.e of 5kg block before collision is

1/2×5×3^2/2^2

=5.625

Answer 2

Answer:5.625

Explanation.