A) Kinetic friction always opposes the motion
B) Kinetic friction can cause the motion
C) Static friction as well as kinetic friction can perform positive work
D) Both [b] and [c]
Correct Answer: D
Solution :
\[{{f}_{k}}\]is responsible for motion of bigger block. Let in above example, if .blocks are not moving relatively then static friction is present but both the blocks will move together and hence \[{{W}_{fk}}\]is positive for bigger block.You need to login to perform this action.
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