A trolley of mass 3 kg moves at a velocity of 8ms-1. trolley B of mass 4kg follows behind trolley A in the same direction at a velocity of 9ms-1 catches up with A and collides with it. after collision trolley A still moves in the same direction but now at a velocity of 9ms-1. calculate the velocity of trolley B after collision

Respuesta :

Let v be the velocity of trolley B after collision. Then by conservation of momentum,

(3 kg) (8 m/s) + (4 kg) (9 m/s) = (3 kg) (9 m/s) + (4 kg) v

Solve for v :

24 kg•m/s + 36 kg•m/s = 27 kg•m/s + (4 kg) v

33 kg•m/s = (4 kg) v

v = (33 kg•m/s) / (4 kg) = 8.25 m/s