The Two Masses in the Figure Are Released from Rest

Multiple Choice

The two masses in the figure are released from rest. After the 3.0-kg mass has fallen 1.5 m, it is moving with a speed of 3.8 m/s. What is the change in mechanical energy done on the system during this time interval by the frictional force on the 2.0 kg mass?

A) (-12 J)
B) (-17 J)
C) (-20 J)
D) (-8.0 J)
E) (-28 J)