Question

A 0.25 kg ball is attached to a 23 cm piece of string. The ball raised so the string is taut and horizontal, the released so that the ball at the bottom of its swing it collides with a 0.21 kg ball that is free to roll along a horizontal table. (Elastic head-on collision)

a) What is the speed of the swinging ball just before the collision?
b) What is the speed of the 0.21 kg ball after the collusion?

Answer 1

I already got a) v=2.1 m/s

Answer 2

http://hyperphysics.phy-astr.gsu.edu/hbase/elacol2.html

Answer 3

so what equation would I use?

Answer 4

I agree with your answer to a). Now, you just need to use the second equation on the c) line from the link above.

Answer 5

I got 0.18 m/s, but that's the wrong answer on my answer sheet

Answer 6

what did you get?

Answer 7

2.3 m/s

Answer 8

how?

Answer 9

using that second equation on line c. on the web link - does it agree with your answer sheet?

Answer 10

ya