Question

The friction coefficient between the horizontal surface  and each of the blocks shown in figure (9-E20) is 0.20.  The collision between the blocks is perfectly elastic. Find  the separation between the two blocks when they come  to rest. Take g = 10 m/s ².

Answer 1

Let velocity of 2kg block on reaching the 4 kg block before collision =u₁.
Given, V₂ = 0 (velocity of 4kg block).
 From work energy principle,

Putting work energy principle for 1^st 2 kg block when come to rest.