Question

1. A particular lever is 90.0% efficient. If 50.0 J of work are done on the lever, then how much work does the lever do on its load? 2.The mechanical advantage of a pulley system is 4.00. Using this pulley system, how much force do you need to exert to lift a 500.0 N box?

Answer 1

Answer:

Explanation:

Using the efficiency formula;

Efficiency = Work done by the machine (output)/work done on the machine (input) ×100%

Efficiency =w/50 ×100

90 = 100w/50

Cross multiply

90×50 = 100W

4500 = 100W

W = 4500/100

W = 45Joules

Hence the lever does 45Joules of work on its load

2) Mechanical Advantage= Load/Effort

Given

MA = 4

Load = 500N

4 = 500/Effort

Effort = 500/4

Effort =125N

Hence the effort required to lift the load is 125N