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vladimir1956 [14]
3 years ago
13

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? 100% because energy must be conserved 90% 25% 18%
Physics
2 answers:
Katyanochek1 [597]3 years ago
6 0
Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
Below is the solution:

Output work = 108 J. 
<span>Input work = 120 J </span>

<span>Efficiency = 108/120 = 9/10 = 90% </span>

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

9966 [12]3 years ago
6 0

Answer:

the answer is 90%

Explanation:

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Answer:

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Explanation:

We must remember that the friction force is defined as the product of the normal force by the coefficient of friction, and it can be calculated by the following expression.

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Now we must calculate the force exerted by means of Newton's second law which tells us that the sum of forces on a body is equal to the product of mass by acceleration.

F - f = m*a

where:

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Now replacing:

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