Which part is not necessary to complete a circuit

This energy transformation diagram represents the energy of a skateboarder moving along a half-pipe. as she skates toward the top of the half-pipe, her original kinetic energy is converted to potential energy and friction. how much of the energy is potential?

What equation is used to calculate the weight of an object on a plant ?

Aball of mass 0.3kg is released from rest at a height of 8m. how fast is it going when it hits the ground? accleration due to gravity is g=9.8m/s