Integrated Physics and Science

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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

• Integrated Physics and Science - ,

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)

• Integrated Physics and Science - ,

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

• Integrated Physics and Science - ,

Southeast Academy Switched-on online?

• Integrated Physics and Science - ,

What is the unit for IMA?

• Integrated Physics and Science - ,

IMA is unitless

• Integrated Physics and Science - ,

yes

• 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?