Three processes are described below. Choose one process in which there is work done on the system. The spring, Earth, and the cart are part of the system.
A relaxed spring rests upright on a tabletop. You slowly compress the spring. You then release the spring and it flies up several meters to its highest point.
A cart at the top of a smooth inclined surface coasts at increasing speed to the bottom (ignore friction).
A cart at the top of a smooth inclined surface slides at increasing speed to the bottom where it runs into and compresses a spring (ignore friction).
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