I am curious why you say the net work and K.E. arenegative? Are you supposed to deduce that before solving theproblem? Even if gravity does positive work and friction doesnegative work, cannot there still be positive net work? Any clarification would be most appreciated. Thanks. David H. Cramster.com student I am curious why you say the net work and K.E. arenegative? Are you supposed to deduce that before solving theproblem? Even if gravity does positive work and friction doesnegative work, cannot there still be positive net work? Any clarification would be most appreciated. Thanks. David H. Cramster.com student
Explanation / Answer
Given : Here The graavity does positive work , because theblock is moving downward. In the other hand the friction does the negtivework . -W = KE2 - KE1 W = - ( KE1 - KE2) W = - ( KE1 - KE2) I hope it helps you