physics
posted by Cynthia .
You exert a force of 455N in pulling 15.0m of rope using a pulley system to lift a 935N object 5.0m. What is the efficiency of the pulley system?
Please help, I appreciate it a lot.

physics 
drwls
Work exerted = Force x Distance = 6825 J
Potential Energy increase: 935x5 = 4675 J
Efficiency = 4675/6825 = ? 
physics 
Anonymous
A person uses a force of 600 N to lift a box from the ground to the top of the ramp shown. Another worker uses a force of 300 N to push the same box up the complete length of the ramp. What is the approximate percent efficiency of the ramp?
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