Question

5. Moving Blobs of Clay Collide. A 5kg blob of clay moving at 2m/s to the right collides inelastically with a blob of clay moving to the left at 2m/s. Afterward, the conjoined blob is moving at 0.5m/s to the right. What was the mass of the blob that was originally moving to the left?

Answer 1

3.0 kg

Step-by-step explanation:

This is a conservation of momentum problem. Total momentum before the collision must equal total momentum after the collision. Momentum = p = mv.

Let x = mass of blob

to the right is the positive direction

(5 kg)(2 m/s) - (x)(2 m/s) = (5 kg + x)(0.5 m/s)

note: I'm going to leave off the unit kg·m/s to save myself some typing!

10 - 2x = 0.5x + 2.5

-2.5x = -7.5

x = -7.5/-2.5 = 3.0 kg