Question

Block ‘ A ‘ is hanging from a vertical spring and is at rest. Block ‘ B ‘ strikes the block ‘A’ with velocity ‘ v ‘ and sticks to it. Then the value of ‘ v ‘ for which the spring just attains natural length is:

Answer 1

Correct option (B)

Explanation:

(B) The initial extension in spring is x₀ = mg/k

Just after collision of B with A the speed of combined mass is v/2 .

For the spring to just attain natural length the combined mass must rise up by x₀ = mg/k (sec fig.) and comes to rest.

Comments

Why energy lossed due to inelastic collision is not considered?