You are given two carts a and b. they look identical and you are told they are made of the same material. you place a at rest at an air track and give b a constant velocity directed to the right so that it collides elastically with a. after the collision cart b moves to the left. what do you conclude?

(a) cart a is hollow.
(b) the two carts are identical.
(c) cart b is hollow.

cart B is hollow

Explanation:

Given

Cart A is initially at rest and cart B is moving towards right and collide with cart A

After collision cart B started moving towards left i.e. mass of cart A is very large as compared to cart B.

Movement of cart B in the direction opposite to initial one Proves that cart B fails to transfer momentum to cart A because cart A is very heavy.

Thus we can conclude cart B is hollow.            

the answer is b i think

the answer is neither ball has a charge.

because if they were both positively charged, they will repel each other.

if they were positively and negatively charged, they will seek.