Answers
A) by conservation of momentum.. mV0=2mV
V=v0/2=5m/sec
B) the collision is elastic means velocity of separation =velocity of approach
velocity of approach =v0=10m/sec
let the v1 and v2 be the velocities of both particles respectively
then mV0= mv2-mv1
and also v0=v1+v2(as collision is elastic)
so v1=0 v2=10m/sec
C) applying conservation of momentum..
mV0=mV2-m10
v2=20m/sec.
.a) conserving momentum
5*10 = 2*5*V( both have same speed)
V = 5m/sec
.b) for elastic collision e = 1
e = U1-U2/V2-V1
and conserving momentum
U1 = V1+V2 ( since masses are same )
by above two equations
V1 = 0 V 2 = 10 m/sec
.c) conserving momentum
we get
10=(V2-10)
V2 = 20 m/sec
.