Question

An alpha-particle of mass m suffers 1-deminsional elastic collision with a nucleus at rest of unknown mass. It is scattered directly backwards losing, 64% of its initial kinetic energy. The mass of the nucleus is :
(A) 2 m (B) 3.5 m
(C) 1.5 m (D) 4 m

Answer 1

Here is ur answer thnks.....

Answer 2

Answer:

4m

mv =mv2-mv1

1/2mv^2=0.36*1/2 mv^2

v1=0=6v

1/2 mv^2=0.64*1/2 mv^2

v2=root of m/m*1/2mv^2

mv==root of mm*0.8v-m*0.6v

1.6m=0.8 root of mm

m=4m