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?

1. The work done by the lever on its load is 45 J

2. The force needed to exert to lift the load is 125 N.

1. Determination of the work done by the lever on the load.

Work Input = 50 J

Efficiency = 90%

Therefore, the work done by the lever on the load is 45 J

2. Determination of the force needed to lift the load

Mechanical advantage (MA) = 4

Load (L) = 500 N

Therefore, the force needed to lift the load is 125 N

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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

the working equation for the angular size is the product of the physical size and 360 degrees divided by the product of two pi and distance from earth. the minimum size would be 0.559 degrees while the maximum size would be 0.49 degrees.