The man having the weight of 150 lb is able to run up a 15-ft-high flight of stairs in 4 s. Determine the power generated. How long would a

Question

The man having the weight of 150 lb is able to run up a 15-ft-high flight of stairs in 4 s. Determine the power generated. How long would a 100-W light bulb have to burn to expend the same amount of energy? Conclusion: Please turn off the lights when they are not in use!

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Thiên Ân 5 months 2021-08-22T07:27:38+00:00 1 Answers 16 views 0

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    2021-08-22T07:28:53+00:00

    Answer:

    t=30.5s

    Explanation:

    Given data

    The weight of man W=150 lb

    The man can run up stairs of height h=15 ft in time t=4s

    The work done by man

    U=Wh\\U=(150)(15)\\U=2250 lb.ft\\

    The power generated by the man

    P_{man}=\frac{U}{t}\\ P_{man}=\frac{2250}{4}\\ P_{man}=562.5lb.ft/s\\or\\P_{man}=562.5lb.ft/s*(1/550)=1.02hp

    Power of bulb

    P_{bulb}=100*(\frac{562.5lb.ft/s}{746W} )=73.73lb.ft/s\\t=\frac{U}{P_{bulb}}=\frac{2250}{73.73} \\ t=30.5s

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