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

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

Answer 2

Answer:A.0

Explanations: dk the letter

And I just did this