A wheel of radius `R` rolls without slipping on the horizontal surface with speed `v_(0)`. When the contact point is `P` on the road, a small patch of mud separates from the wheel at its highest point strikes the road at point `Q`. Find distance `PQ`.

Explanation

The velocity with which the mud particle separates is `2v`.
projectile motion: `2R=(1)/(2)"gt"^(2)implies t=sqrt((4R)/(g))`
`PQ=x=2vt=2vsqrt((4R)/(g))=4vsqrt((R)/(g))`