Question

A weightlifter exerts an upward force on a 1000-N barbell and holds it at a height of 1 meter for 2 seconds. Approximately how much power does the weightlifter exert on the barbell during this time?

Answer 1

The weightlifter exerts approximately 500 watts of power on the barbell during this time.

Step-by-step explanation:

The power exerted by the weightlifter can be calculated using the formula:

Power = Work / Time

First, we need to calculate the work done by the weightlifter. Work is given by the formula:

Work = Force x Distance

In this case, the weightlifter exerts an upward force of 1000 N on the barbell and holds it at a height of 1 meter. So, the work done is:

Work = 1000 N x 1 m = 1000 J

Now, we can calculate the power:

Power = 1000 J / 2 s = 500 W

Therefore, the weightlifter exerts approximately 500 watts of power on the barbell during this time.

Answer 2

Amount of work done is zero and so power = 0 watts.

Step-by-step explanation:

Power is the rate at which work is done, or W divided by delta t. Since the barbell is not moving, the weightlifter is not doing work on the barbell.Therefore, if the work done is zero, then the power is also zero.It may seem unusual that the data given in question is versatile i.e. A weightlifter exerts an upward force on a 1000-N barbell and holds it at a height of 1 meter for 2 seconds. But, still the answer is zero watts , this was a tricky question although conceptual basis of question was good! Power is dependent on amount of work done which is further related to displacement and here the net displacement is zero ! Hence, amount of work done is zero and so power = 0 watts.