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3 years ago

10

An athlete is working out in the weight room. he steadily holds 50 kg above his head for ten seconds which statement is true abo

ut this situation.
1 the athlete isn't doing any work because he doesn't move the weight.
2 the athlete isn't doing any work because he doesn't hold the weight long enough.
3 the athlete is doing work because he prevents the weight from falling down.
4 the athlete is doing work because 50 kg is a significant load to lift.

1 answer:

Andrews [41]3 years ago

5 0

Hi. The answer to your question is the first option.

The athlete isn’t doing any work because he doesn’t move the weight.

Hope this helps :))

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By using the kinematics equation to determine the speed of the water in the bucket and applying the equation of continuity to estimate the diameter of the column, we have the following;

Using the kinematics equation:

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$\mathbf{A_iV_i = A_fV_f}$

$\mathbf{\pi r^2_iV_i = \pi r^2_fV_f}$

$\mathbf{ r^2_iV_i = r^2_fV_f}$

$\mathbf{ (\dfrac{10}{2})^2\times 2.0 = r_f^2 \times 12.29}$

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$\mathbf{ r_f= \sqrt{\dfrac{50}{12.29} }}$

$\mathbf{ V_f= 2.02 \ cm }$

Since diameter = 2r;

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