A block of mass `5 kg` rests on a rough horizontal surface. It is found that a force of `10 N` is required to make the block just move However , once the motion begains, a force of only `8 N` is enough to maintain the motion find the coefficient of kinetic and static friction between the block and the horizontal surface

Explanation

Hence `f_(l) = 10 N rArr mu_(s) mg= 10 `
`rArr mu_(s) = (10)/(mg) = (10)/(5 xx 10)= 0.2`
`f_(k)= 8 N rArr mu_(k) mg 8`
`rArr mu_(k) = (8)/(mg) = (8)/(5 xx 10)= 0.16`