Question

A block weighing 10 N travels down a smooth curved track AB joined to a rough horizontal surface (figure 8-E5). The rough surface has a friction coefficient of e20 with the block. If the block starts slipping on the track from a point 1'0 in above the horizontal surface,how far will it move on the rough surface ?

Answer 1

$mg=10N,\mu =0.2,H=1m,u=v=0$

Change in P.E =Work done to increase K.E.

$\Rightarrow W=mgh=10\times 1=10J$

Again on the horizontal surface the frictional force

$F=\mu R=\mu mg=10\times 1=10J$

So, the K.E. is used to overcome friction.

$\Rightarrow S=\frac{W}{F}=\frac{10J}{2N}=5m$