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 0.20 with the block. If the block starts slipping on the track from a point 1.0 m above the horizontal surface, how far will it move on the rough surface?

Question

Philoid · Accepted Answer

Coefficient of friction, μ = 0.20

Weight of the block = 10 N

Height of the point A, h = 1.0 m

Frictional force exerted on the block by the rough surface, F = μ × weight of the block

= 0.20 × 10

= 2 N

Let the displacement of the box from point A be s

Loss in potential energy = Work done by the frictional force = Fs

Weight of the block × h = 2 × s

10 × 1 = 2 × s

s = 5 m

∴ The block will move 5 m before stopping on the rough surface.