Question

A car of mass 120kg moving with a velocity of 30m/s overtake and collide with another car of mass 100kg moving with at 12m/s.After collision the two car separate with a relative velocity of 4m/s
(1)calculate the velocity each car
And
(2) The loss in kinetic after collision

Answer 1

m1 = 120
v1 = 30
P1 = m 1 v1 = 3600

m2 = 100
v2 = 12
P2 = m2 v2 = 1200

Total momentum before = P
P = 3600 + 1200
P = 4800
THE momentum after is THE SAME P
first mass speed after = u1
u2 = (u1+4)
so 4800 = 120 u1 + 100(u1+4)
solve for u1 and u2

Ke before = (1/2) 120 * 30^2 + (1/2) 100 * 12*2
Ke after = (1/2) 120 * u1^2 + (1/2) 100 * u2^2
subtract

Answer 2

Thanks man