Class 11 NEET Physics Work, Energy and Power Questions

Here,m1=m,m2=2m
u1=2

m

s

,u2=0
Coefficient of restitution, e = 0.5
Let v1 and v2 be their respective velocities after collision.
Applying the law of conservation of linear momentum,
we get
m1u1+m2u2=m1v1+m2v2
∴m×2+2m×0=m×v1+2m×v2
or 2m=mv1+2mv2
or 2=(v1+2v2).......(i)
By definition of coefficient of restitution,
e=

v2−v1

u1−u2

or e(u1−u2)=v2−v1
0.5(2−0)=v2−v1
1=v2−v1........(ii)
Solving equations (i) and (ii), we get
v1=0

m

s

,v2=1

m

s