Power only g6 ppt
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Transcript of Power only g6 ppt
Calculating Work• Work = force (N) x distance (m)
• W = F x D
• The unit for work is a Joule (J).
• If you lifted an object weighing 1N through a distance of 1m, you did 1 Joule of work:
W = FD = 1N x 1m = 1 J
Think about how much force a Newton is…about ¼ of a pound. No!
Calculating Work
•If you lifted an object weighing 200 N through a distance of 0.5m, how much work would you do?
Calculating Work•If you lifted an object weighing 200 N through a distance of 0.5m, how much work would you do?
Work = force x distance = 200 N x 0.5m = 100 J.
Using stairs………..
Using Elevator………
..
What is the main difference between going up using an elevator and using the stairs?
It is the “ Time “
When work done is related to time …….
WE call it
Power•Power is the rate at which work is done , or the amount of work per unit of time.
Two men can move a lot of sand using shovels…
…but a front-end loader can do it in less time…
…because the front-end loader has more POWER.
Power•Power is the rate at which work is done , or the amount of work per unit of time.
•Power = work / time or
•Power = force x distance / timeBecause work = force x distance
Power•The unit for power is watt (W). One watt is equal to 1 joule per second (1 J/sec).
•Large quantities of power are measured in kilowatts (kW).
•One kilowatt equals _____ watts.1000