posted by Anonymous .
The efficiency of a pulley system is 81 percent. The pulleys are used to raise a mass of 85 kg to a height of 8.5 m. The acceleration of gravity is 9.81 m/s^2. What force is exerted on the rope of the pulley system if the rope is pulled for 14 m in order to raise the mass to the required height?
This whole website is useless...:P