Question

A body of mass 5 kg strikes another body of mass 2.5 kg at rest. after collision the bodies stick together and move with K.E. f 5J.The K.E of the first body before collission

Answer 1

Answer:

Since it is elastic collision we conserve the momentum..

Explanation:

m1=5kg m2=2.5kg v1=x v2=0

k.e of combined system = 5 = 1/2*mv*2

5*2=7.5v*2

10/7.5=v*2. v=(10/7.5)*1/2

5*x+2.5*0=7.5*[(10/7.5)*1/2]

x=[(7.5)*1/2][(10)*1/2]/[5]