1. A student of mass 40 kg caries a bag weighing 5000g from the ground floor to his class on the first floor that is 700 cm high. The work done by the boy is =

answer should be fraction

A heavy rope, 50 ft long, weighs 0.3 lb/ft and hangs over the edge of a building 140 ft high. (a) How much work W is done in pulling the rope to the top of the building? W = ft-lb (b) How much work W is done in pulling half the rope to the top of the building? W = ft-lb

Problem 2: A certain spring has a spring constant k₁ = 660 N/m as the spring is stretched from x = 0 to x1 = 35 cm. The spring constant then changes to k₂ = 250 N/m as the spring is stretched to x2= 65 cm. From x₂= 65 cm to x3 = 89 cm the spring force is constant at F3 = 105 N.