Question

A weightlifter curls a 25 kg bar, raising it each time a distance of 0.50 m. How many times must he repeat this exercise to burn off the energy in one slice of pizza? Assume 25% efficiency. Energy content of one slice of pizza is 1260 kJ .

Answer 1

42 times must he repeat this exercise to burn off the energy in one slice of pizza.

What is energy?

Energy is the ability or capability to do tasks, such as the ability to move an item (of a certain mass) by exerting force. Energy can exist in many different forms, including electrical, mechanical, chemical, thermal, or nuclear, and it can change its form.

Energy burn by the weightlifter = potential energy

Potential energy = mgh

Potential energy = 25.(9.8)(0.50)

Potential energy = 122.5 Joule.

Assume 25% of efficiency so energy burn = 122.5*25/100

energy burn = 30.625 joule

Number of times = 1260/30.625

Number of times = 42 times.

42 times must he repeat this exercise to burn off the energy in one slice of pizza.

To learn more about energy refer to the link:

brainly.com/question/1932868

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