A block must be moved from the ground to a platform high
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A 3.0kg block must be moved from the ground to a platform 2.5m high. Three different frictionless paths are proposed:
(a) For each path, calculate the work done on the block by the gravitational force. Express each answer with the correct sign and units.
(b) Based on your results, state whether the gravitational force is conservative. Provide a clear justification rooted in your calculations.
(c) Taking the ground as the zero-potential reference, derive an algebraic expression for the gravitational potential energy of the block–Earth system at an arbitrary height h.
(d) If the block is released from rest at the top of the ramp described in Path 2 and allowed to slide back down without friction, determine its speed just as it reaches the ground.