The curved portions are smooth and horizontal surface is rough. The block is released from P. At what distance from A, it will stop (if μ = 0.8)?

The distance travelled by the block on the rough surface can be calculated from energy conservation.Ki+Ui=Kf+Uf+WFwhere, Wf  = work done by friction.⇒0+mgh=0+0+μmgs⇒s=hμ=10.8=1.25 m The bllock stops at distance 1.25 m from A.