Question

A crane lifts a load by means of a pulley. The wheel of the pulley has adiameter of 42 cm. The load is pulled up at a uniform rate of 0.8 m/s andtakes two minutes to reach the desired level. Calculate the number ofcomplete revolutions the wheel makes to raise the load.​

Answer 1

Answer:

diameter : 0.4 m

radius : 0.2 m

distance covered by load : 0.8 * 120 = 96 m

in one revolution : 2 * 3.14 * 0.2 = 1.2 m

in 96 m = 96/1.2 = 80 rev