# Gravitational Potential Energy to Kinetic Energy

When a yo-yo is released from a height $h$, the gravitational potential energy is converted to kinetic energy. However, the yo-yo obviously has less acceleration than $g$, $9.8\frac{m}{s}$. This means that the final speed of the yo-yo is less than what it would be if it were in free fall. It seems that the kinetic energy at the end is less than the potential energy at the beginning. What happened to the rest of the energy?