Questions: Part C Because we are ignoring friction, no thermal energy is generated and the total energy is the mechanical energy, the kinetic energy plus the potential energy: E=K+U. Observe the total energy bar on the Bar Graph. As the skater is skating back and forth, which statement best describes the total energy? smallest at the locations where the skater turns to go back in the opposite direction and greatest at the lowest point of the track. The total energy is the same at all locations of the track. greatest at the locations where the skater turns and goes back in the opposite direction and smallest at the lowest point of the track.

Solution Steps

Mechanical energy is the sum of kinetic energy (\(K\)) and potential energy (\(U\)). In a frictionless system, the total mechanical energy (\(E\)) remains constant as the skater moves along the track. This is because energy is conserved, and there is no energy loss due to friction.

As the skater moves along the track:

• At the highest points (where the skater turns to go back), the potential energy is at its maximum, and kinetic energy is at its minimum.
• At the lowest point of the track, the potential energy is at its minimum, and kinetic energy is at its maximum.

• The first statement suggests that the total energy is smallest at the turning points and greatest at the lowest point. This is incorrect because the total energy should remain constant.
• The second statement suggests that the total energy is the same at all locations, which aligns with the principle of conservation of energy in a frictionless system.
• The third statement suggests that the total energy is greatest at the turning points and smallest at the lowest point, which is also incorrect.

Final Answer