Answer:
50 N
Explanation:
Efficiency of a machine can't be more than 1, so I assume you mean 40%. (Remember, efficiency and mechanical advantage are not the same).
Efficiency is the ratio of work out of a system to the work in to the system.
e = Wout / Win
Work is force times distance, so:
e = (Fout × Dout) / (Fin × Din)
Rearranging:
Fin = (Fout × Dout) / (e × Din)
Fin = (Fout / e) × (Dout / Din)
Fin = (Fout / e) / (Din / Dout)
We know that e = 0.40, and Fout = 120 N. Since there are 6 pulleys, we also know that Din/Dout = 6.
F = (120 N / 0.4) / 6
F = 50 N
The electric field is given by volts/distance:
. The breakdown voltage of dry air is about 3x10^6V/m. So solving for V we get
or
C.<span>a stable internal attribution</span>
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