1. The problem statement, all variables and given/known data Particles of mud are thrown from the rim of a rolling wheel. If the forward speed of the wheel is v0, and the radius of the wheel is b, show that the greatest height above the ground that the mud can go is b + v02 / 2g + gb2/ 2v02 At what point on the rolling wheel does this mud leave? (Note: It is necessary to assume that v02≥bg.) 2. Relevant equations In 3 dimensions concept, r = i b cosθ + j b sinθ Since v = rω = rθ', v = dr / dt = (-b sin θ i + b cos θ j) θ' = -v0 ( -sin θ i + cos θ j ) 3. The attempt at a solution Firstly, find the time when the particle meets maximum height. Take downwards as positive for vertical direction, v = u + at 0 = v0 cos θ + g t Then I find the time with minus sign. It sounds quite weird. In case, how do I know which side of rim the particle is thrown from rolling wheel? The forum has already posted that problem already but still I have no idea with it. Thanks.