Respuesta :
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
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%
Work Output =?
[tex]efficiency \: = \frac{work \: output}{work \: input} \times 100 \\ \\ 90\% = \frac{work \: output}{50} \\ \\ cross \: multiply \\ \\ work \: output \: = 90\% \: \times 50 \\ \\ work \: output = 0.9 \: \times 50[/tex]
Work Output = 45 J
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
Effort (E) = ?
[tex]mechanical \: advantage \: = \frac{load}{effot} \\ \\ 4 \: = \frac{500}{effort} \\ \\ cross \: multiply \\ \\ 4 \: \times effort \: = 500 \\ \\ divide \: both \: side \: by \: 4 \\ \\ effort \: = \frac{500}{4} \\ [/tex]
Effort = 125 N
Therefore, the force needed to lift the load is 125 N
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