Question

1. which statement is correct about the potential energy of a car moving down a ramp? (1 point)

potential energy depends on the mass and velocity of the car.
potential energy is highest when the car reaches the bottom of the ramp.
potential energy remains constant because total energy is constant.
potential energy is highest when the car is released at the top of the ramp.

Explanation:

• Potential energy formula is \(PE = mgh\) (where \(m\) is mass, \(g\) is acceleration due to gravity, \(h\) is height). Velocity affects kinetic energy (\(KE=\frac{1}{2}mv^{2}\)), not potential energy. So the statement "Potential energy depends on the mass and velocity of the car" is wrong.
• As the car moves down the ramp, \(h\) (height) decreases. Since \(PE = mgh\), potential energy decreases. At the bottom of the ramp (\(h = 0\) if we take the bottom as the reference level), \(PE=0\) (minimum, not maximum). So "Potential energy is highest when the car reaches the bottom of the ramp" is wrong.
• Total mechanical energy (\(E=PE + KE\)) is constant (assuming no non - conservative forces like friction). But \(PE\) decreases and \(KE\) increases as the car moves down. So "Potential energy remains constant because total energy is constant" is wrong.
• At the top of the ramp, \(h\) is maximum. Using \(PE = mgh\), potential energy is highest at the top.

Answer:

Potential energy is highest when the car is released at the top of the ramp.