Work and Power

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Work and Power

Class Notes: while viewing this Power Point, fill in the Work and Power Note sheet given.

What is Work?

Work is a force exerted on an object that causes the object to move some distance.

• Force without moving a distance yields NO WORK !!!!

• In other words, if a force is applied to an object and the object DOES NOT MOVE , then no work has been done.

• Example #1 : If you push on a wall until your arms are sooooooo tired you can’t push anymore and the wall doesn’t move……..then you have done no work.

• Example #2: If you blow on a piece of paper and it moves……….you have done more work than in example #1.

• In order for work to be done on an object, the force you apply must be in the same direction as the movement of the object.

Work can be calculated!!!!

• Work = Force x Distance

The SI Unit for Work is Joule

• 1 Joule = 1 Newton x 1 Meter

• Fun Fact: The Joule is named in honor of James Prescott Joule, an English

Physicist who worked extensively with different forms of energy.

Hint: we will solve work word problems!!!!

What is Power????

Power is the rate at which work is done (yes work and power are related!!!)

• Power can also be described as the rate energy is transferred from one object to another or the rate energy is converted.

• Power was once measured in

Horsepower

.

• Fun Facts:

• Horsepower is an American unit of power

• Horsepower equals the amount of work a horse does.

• The power of a car or truck is measured in Horsepower (this is because when the first cars were built people did not trust “the horseless carriages!)

Power can be calculated too!!!!

π‘·π’π’˜π’†π’“ =

π‘Ύπ’π’“π’Œ

π‘»π’Šπ’Žπ’†

• The SI Unit for Power is Watt.

• Fun Fact: The Watt is named in honor of the

Scottish Inventor James Watt (who also coined the term Horsepower)

• 1 Watt =

1 π½π‘œπ‘’π‘™π‘’

1 π‘†π‘’π‘π‘œπ‘›π‘‘

• 1 Watt is approximately the power required to raise a glass of water to your mouth in 1 second.

• Second Hint: we will calculate power too!

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