# Work and Power

## 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 work has been done.

DOES NOT MOVE

, then no • 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 = 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 =

𝑾𝒐𝒓𝒌 𝑻𝒊𝒎𝒆 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 𝐽𝑜𝑢𝑙𝑒 1 𝑆𝑒𝑐𝑜𝑛𝑑 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!