Answer: The velocity of the ball the ball after collision is 5.5 m/s.
Explanation:
John hitting the bottle which is at rest means this is an Elastic collision.
Mass of the ball= \(M_1=0.4 kg\)
Velocity of ball before collision = \(U_1=18m/s\)
Velocity of ball after collision =\(V_1\)
Mass of the bottle= \(M_2=0.2 kg\)
Velocity of bottle before collision = \(U_2=0 m/s\)(bottle is at at rest)
Velocity of bottle after collision =\(V_2=25 m/s\)
\(M_1V_1+M_2V_2=M_1U_1+M_2U_2\)
\(V_1=\frac{(0.4 kg\times 18 m/s+0.2 kg\times 0m/s)-0.2 kg\times 25m/s}{0.4}\)
\(V_1=5.5 m/s\)
The velocity of the ball the ball after collision is 5.5 m/s.
