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| Version | User | Scope of changes |
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| Dec 15 2006, 11:10 AM EST (current) | 29836jg | |
| Dec 13 2006, 4:16 PM EST | 29836jg |
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Unit 6 Work and Machines
Power
Definition: Amount of work done in a certain amount of time; rate at which work is done.
Explanation/Notes: Power is the amout of work done in a certain amount of time and the formulas are power equals work divided by time and power equals energy divided by time. Power is measured in Watts.
Rock Climbers climb at a very slow rate, which keeps they're power small.
Formula: P=W/T & P=E/T
Units: Power is measured in watts (W).
Sample Problem:
Calculate the Power if:
It takes 3 seconds to move a 100 Newton object 25 meters.
W=F*D
P=W/T
D= 25 meters
F= 100 Newtons
T= 3 Seconds
P= (25m)(100N)/3 sec
Everyday Example:
If you rockclimb at a slow rate, your power will be slow, but if you rockclimb at a faster rate then your power will increase.
Image:
This picture shows a woman walking and running up the stairs. The work is the same, but more power is needed to do it faster.
Video: Sample Problems
