Question

Object A is 8 kg and at rest and Object B is 16 kg and moving at 10 m/s to the Right. If Object B hits Object A and Object B is at rest after the collision, what is the velocity of Object A after the collision? Why?

Answer 1

Initially...

Object A is at rest(v=0)

With Mass =8kg

Object B moving at 10ms- and Mass of 16kg.

Now After collision(Elastic)... B Came to rest...Meaning its final vel =0

But its mass remains the same

What velocity would A be moving with?

From Conversation of Momentum

M'U' + M"U"= M'V' + M"V"

8(0) + (16)(10) = 8V' + 16(0)

0 + 160 = 8V' + 0

8V'= 160

V'= 160/8

V'=20ms-¹.

A would be Moving at 20ms-¹ after collision.