A traveller has to raise a suitcase of mass from the ground level to a platform higher
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A traveller has to raise a suitcase of mass 18kg from the ground level to a platform 1.5m higher. Two alternative routes are possible:
Route A: Lift the suitcase vertically upward through 1.5m.
Route B: Pull the suitcase up a smooth ramp of length 3.0m inclined at 30∘ to the horizontal. While moving along the ramp, a constant horizontal force of 40N due to air drag opposes the motion and the coefficient of kinetic friction between the suitcase and ramp is 0.15.
(i) Calculate the work done on the suitcase by the traveller in lifting it directly along Route A.
(ii) For Route B, determine the total work done on the suitcase by (a) the component of its weight along the ramp, (b) kinetic friction, and (c) air drag during the 3.0m ascent.
(iii) From your answers to parts (i) and (ii), decide which route requires less work by the traveller. Suggest one practical way, apart from choosing the route, to further reduce the amount of work needed to raise the suitcase to the same height.