A body sliding on a smooth inclined plane requires 4 s to reach the bottom, starting from rest at the top. How much time does it take to cover one-fourth the distance starting from rest at the top?

When a body slides on an inclined plane, component of weight along the plane produces an acceleration.a=mgsinθm=g sin θ = ConstantIf s is the length of the inclined plane, then s=0+12at2=12gsinθ.t2s's=t'2t2or  ss'=t2t'2, Given t = 4 s and s'=s4t'=ts's=4s4s=42=2s