A student skates up a ramp inclined at 30°. Starting at the bottom with speed v₀, the student turns around along a semicircular path xyz of radius R and reaches maximum height h at y. Energy loss is negligible, and at y the required centripetal force is provided only by weight. Choose the correct statements.

Question

G1 Physics · Accepted Answer

At the highest point y, the component of gravity within the ramp plane toward the centre is g sin30°=g/2. Thus vᵧ²/R=g/2, so vᵧ²=gR/2. Energy gives v₀²-2gh=vᵧ²=gR/2, so A is true. At x and z the speed is larger than at y, making the required centripetal force maximum there, so D is true. Hence A,D.