Question
Question: Two identical balls A and B are released from the position shown in the figure. They collide elastic...
Two identical balls A and B are released from the position shown in the figure. They collide elastically on the horizontal portion. The ratio of heights attained by A and B after collision is (neglect friction) –
A
1 : 4
B
2 : 1
C
4 : 13
D
2 : 5
Answer
4 : 13
Explanation
Solution
When the two balls collide with each other as the mass of the two balls is equal they exchange their velocities on colliding elastically speed of the ball B when it reaches back to the initial position
3mgh = 21mv2 ̃ v = 6gh
Height reached by the particle B (from highest point on the incline)
HB = 49h ; total height = h + 49h=413h
After collision when particle reaches the max. height = h
Ratio = HBHA=134