Question

If an object is moving at `40 m/s` over a surface with a kinetic friction coefficient of `u_k=12 /g`, how far will the object continue to move?

Answer 1

By conservation of mechanical energy
Work done against kinetic frictional force = KE of the body
`mu_kmgxxd=1/2xxmv^2`
where m = mass
`mu_k=12/g`= kinetic frictional coefficient
`v=40m/s`= velocity
`d`= distance moved
or,`d=v^2/(2mu_kg)=40^2/(2xx12/gxxg)=192m`