Question

Mr. Starr pushed a cart full of groceries to his car. After emptying the cart, he pushed it back to the store. He pushed the cart at a speed of 2 meters per second each way. Which is the best prediction?(1 point)
Responses

The cart had the same kinetic energy going each way.
The cart had the same kinetic energy going each way.

The cart’s kinetic energy depends on Mr. Starr’s mass.
The cart’s kinetic energy depends on Mr. Starr’s mass.

When it was empty, the cart had less kinetic energy.
When it was empty, the cart had less kinetic energy.

When it was full, the cart had less kinetic energy.
When it was full, the cart had less kinetic energy.

Answer 1

When it was empty, the cart had less kinetic energy.

Explanation: KE = 1/2 m v^2. Since the speed v was the same both ways, the cart with smaller mass (empty) had less kinetic energy than the full cart.