First, let's calculate the total mechanical energy when the block is at rest and the spring is compressed 5 cm:

Now, let's use this total energy to calculate the velocity when the spring is compressed by 2.5 cm:

Therefore the speed is 1.026 m/s.
Answer:
Mass and Velocity
Explanation:
Momentum = Mass X Velocity
or p=m' x v
since in physics p is quantity momentum and m stands for mass and v stands for velocity.
Hope this helps :)
it would be at either A or B.