Please let me know if I am on the right track for these problems.(adsbygoogle = window.adsbygoogle || []).push({});

1) A weight lifter picks up a barbell and

1. lifts it chest high

2. holds it for 5 minutes

3. puts it down.

Rank the amounts of work W the weight lifter performs during this three operations. Label the quantities as W1, W2, and W3. Justify you ranking order. ---> I think that the most amount of work is when it is lifted chest high, since there is a force and displacement involved. After that, would me when he puts it down, becuase gravity helps, and there is a displacement. When he holds it up for five min there is no work becuase there is no displacement.

2)Estimate the amount of work the engine performed on a 1200 kg car as it accelerated at 1.2 m/s2 over a 150 meter distance. ----> Well since the equation for work is force times distance, it would be (1.2 m/s2)(1200kg)(150m) So the total work would be 216,000 J

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# Homework Help: Work and Energy

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