A porter carrying his own mass of 60 ,kg and luggage of mass 20 ,kg climbs a flight…
PHYSICS · Multi-part · CBSE · Physics · Work and Energy · Work and Energy
Problem
A porter carrying his own mass of 60\,kg and luggage of mass 20\,kg climbs a flight of stairs. First he rises 3\,m, rests on a landing, and then climbs a further 2\,m to reach the next floor. Take g=10ms−2.
(i) Find the total work done by the porter–luggage system against the gravitational field during the entire climb.
(ii) Calculate the work that would have been required if an elevator had carried him straight up through the same total vertical height of 5\,m.
(iii) Show that the answers to parts (i) and (ii) are identical, and state what this reveals about the work done against gravity.