AP Physics 1easymcq1 pt
A 3.0 kg box slides 5.0 m across a floor against a constant 9.0 N friction force. The work done by friction is
A.-45 J
B.45 J
C.-15 J
D.-27 J
Explanation
Core Concept
Friction opposes motion, so W = −Fd = −(9.0)(5.0) = −45 J.
Correct Answer
A-45 J
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