Power
The rate at which work is done (or at which energy is used up/transferred) 1
In your reference table, find the equation for power
W
P= t
Where
P ­­ power
W ­­ work
t ­­ time
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Is power a vector or a scalar? 3
Use dimensional analysis to derive the unit for power
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Additional power equations: 6
Atlas and Hercules, two carnival sideshow strong men, each lift 200. kg barbells 2.00 m off the ground. Atlas lifts his barbells in 1.00 s and Hercules lifts his in 3.00 s. ﴾a﴿ Which man does more work? ﴾b﴿ Calculate which man is more powerful.
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A man weighing 1000 N runs up some stairs , rising a vertical height of 5 m in 10 seconds. What power does he develop? What are the energy transfers here? 8
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An electric lamp is rated 100 Watts. How many joules of electrical energy are transformed into heat and light
(a) during each second
(b) during a period of 100 seconds 10
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