In one experiment, the students allow the block to oscillate after stretching the spring a distance A. If the potential energy stored in the spring is U0, then what is the change in kinetic energy of the block after it is released from rest and has traveled a distance of A2?

K = m g (A - A2)

Explanation:

In a block spring system the total energy is the sum of the potential energy plus the kinetic energy, for maximum elongation all the energy is potential

Em = U₀ = m g A

For when the system is at an ele

Elongation A2 less than A, energy has two parts

Em = K + U₂

K = Em - U₂

We substitute

K = m g A - m gA2

K = m g (A - A2)