Kinetic and Potential Energy

Which statement accurately distinguishes between kinetic energy and potential energy?

• Kinetic energy is energy of position, while potential energy is energy of motion.

• Kinetic energy is energy of motion, while potential energy is energy of position.

• Kinetic energy is stored energy, while potential energy is energy of movement.

• Kinetic energy is thermal energy, while potential energy is mechanical energy.

In a closed system where only gravitational forces are at play, what happens to the total mechanical energy (sum of kinetic and potential energy) of an object?

• It continuously increases as the object moves.

• It continuously decreases due to energy loss.

• It remains constant, converting between kinetic and potential forms.

• It is entirely converted into thermal energy.

When friction is introduced into a system involving a moving object, how does it affect the total mechanical energy of the system?

• Friction increases the total mechanical energy by adding heat.

• Friction converts mechanical energy into thermal energy, reducing the total mechanical energy.

• Friction has no effect on the total mechanical energy.

• Friction converts potential energy directly into kinetic energy.

A 75 kg skateboarder is at the top of a ramp, 8 meters above the lowest point. Assuming the gravitational field strength is 9.8 m/s², what is the gravitational potential energy of the skateboarder relative to the lowest point?

• 75 J

• 590 J

• 5900 J

• 7500 J