Question

Work of 36 joules is done on ball A. It travels a certain distance and hits ball B. Ball B, which was stationary, starts to move at 12 m/s. If this is an elastic collision, then what was the initial velocity of ball A? (Both balls have a mass of 500 g. Ignore changes due to friction.)

Answer 1

Answer:A.0

Explanations: dk the letter

And I just did this

Answer 2

here collision between two balls is perfectly elastic collision

and the friction force is considered to be zero

now here we can say that momentum conservation is applicable here

`m_1v_(1i) + m_2v_(2i) = m_1v_(1f) + m_1v_(2f)`

here we know that two balls are of same mass then we can say

`m*v + m*0 = m_1v_(1f) + m_1v_(2f)`

divide whole equation by mass "m"

`v = v_(1f) + v_(2f)`

now it is also given that it is elastic collision between two balls

`v_(2f) - v_(1f) = v_(1i) - v_(2i)`

`v_(2f) - v_(1f) = v - 0`

now by solving the above two equations we have

`v_(2f) = v`

`v_(1f) = 0`

so here given that

`v_(2f) = v = 12 m/s`

so the initial speed of ball A was same as final speed of ball B which is given as 12 m/s.

So here final answer will be 12 m/s