Question

A block is projected along a rough horizontal road with a speed of 10 m/s. If the coefficient of kinetic friction is 0.10, how far will it travel before coming to rest?

Answer 1

Due to friction the body wil decelerate. Let the deceleratin be a.
`R-mg=0`
`rarr R=mg`……….ii
Again `ma-muR=0`
`rarr ma=mu mg`
`rarr a=mug=0.1xx10`
`=1m/s^2 `
Initial velocity `u= 10 m/s `
FiN/Al velocity, `v=0m/s`
`a=-1 m/s^2 (deceleration)
`S=(v^2-u^2)/(2a)`
`=0-(10^2)/2(-1)`
`=100/2 = 50 m` It will travel 50 m before coming to rest.