# Integrated Physics and Science

A crowbar is used as a lever. The effort force of 40 newtons moves 3 meters. The resistance force of 54 newtons moves 2 meters. What is the efficiency of the lever?

A) 100% because energy must be conserved
B) 90%
C) 25%
D) 18%

i need help. i don't know how to figure this one out

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1. Output work = 108 J.
Input work = 120 J

Efficiency = 108/120 = 9/10 = 90%

(Energy can be converted to heat in friction at the fulcrum, or useless potential energy distorting the crowbar)

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2. oh okay. i get it now. Thank you very much

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4. What is the unit for IMA?

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5. IMA is unitless

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6. yes

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7. A crowbar is used as a lever. The effort force of 40 newtons moves 3 meters. The resistance force of 54 newtons moves 2 meters. What is the efficiency of the lever?

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