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3 years ago

A weightlifter expends 294 w of power lifting a weight to a height of 2 m in 10 seconds. what mass has he lifted?

1 answer:

3 0

The power of the weightlifter is equal to the ratio between the work done by it and the time taken:
$P= \frac{W}{t}$
since we know the power and the time, we can find the work done:
$W=Pt=(294 W)(10 s)=2940 J$

For the work-energy theorem, this work done by the lifter is equal to the gravitational potential energy gained by the mass, which is given by:
$U=mg \Delta h$
where m is the mass and $\Delta h$ is the increase in height. Rearranging the formula and using W=U, we can find the mass:
$m= \frac{U}{g\Delta h}= \frac{2940 J}{(9.81 m/s^2)(2 m)}=149.8 kg$

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3 years ago

A 60cm long string of an ordinary guitar is tuned to produce the note a4 (frequency 440hz) when vibrating in its fundamental mod

pishuonlain [190]

Answer:

0.78 m

Explanation:

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3 years ago

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evablogger [386]

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4 years ago

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mafiozo [28]

Answer:

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Explanation:

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