Question

m1 and m2 are two blocks placed one above other. There is no friction between the lower block and ground. The lower block is being pushed by a constant horizontal force F. There is sufficient friction between the blocks so that they dont slip over each other. Find the work done by friction on upper block from ground frame as the arrangement moves through S.

Answer 1

$$\begin{gathered} Theforceontheupperblockduetheforceappliedonthelowerblock \\ incontactofthegroundisgivenby; \\ {m}_{2}a=F-\mu m_{2}g \\ Theworkdoneontheuppermass{m}_2=W=Force\times S=m_{2}a\times S=\left(F-\mu m_{2}g\right)\times S \end{gathered}$$