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wakawu
Lv 5
wakawu asked in Science & MathematicsPhysics · 1 decade ago

Physics power question?

A small hoist can raise 100kg of bricks to the top of a construction project 30m above the street in half a minute. Determine the power provided.

I'm a little confused how to start this problem but here is what I got so far. Did I go about this right at all?

t = 30s, m = 100kg, a = 9.81

I used formula V(final)*2 = V(initial)*2 - 2(g)y

V(final) = 24.26 m/s

a = {V(f) - V(i)} / t = 0.8086 s

F=ma = 100(0.8086) = 80.8N

P=W/t so is it {80.8(30)} / 30 = 80.8 W ??

1 Answer

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  • Anonymous
    1 decade ago
    Favorite Answer

    P=W/t

    W= F*d = mg*d

    P = mg*d/t = 100 kg * 9.8 N/kg * 30 m / 30 s = 980 W

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