Question

determine the quantity of work done when a crane lifts a 100-n block from 2m above the ground to 6m above the ground

Answer 1

100n divided by 8m because 2m and 6m are like terms. Hope that helps:)

Answer 2

Work done = Force.Δx                                                                                  
Work done = 100(6-2). cos(180°) = -100 (4) = -400 J. 
Work done is negative because force acting on the block and its displacement are in opposite direction. Hope this helps!