1.) Two people of the same mass climb the same flight of stairs. The first person climbs the stairs in 25 s; the second person does so in 35 s.
a) Which person does more work?Explain
b) Which person produces more power?Explain

2.) Lee pushes a 20 kg mass 10 m across a floor with a horizontal force of 80 N. Calculate the amount of work Lee does.

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1. 1a) W1=W2 = mgh
2a) P1 > P2 , mgh/25 >mgh/35

2) W=Fs=80•10 =800 J

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2. The work done = potential energy gained = m g h.
That is the same for both since m, g and h are the same for both

The power is the work per unit time.

Power = m g h/t
so smaller t ---> bigger power

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3. Calculate the work done when a person push acar from stationany position to a

distance of 50m appliny a. force of 200n.

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