What is work?What is work?

Do I get paid for work?

Is my definition of work different than the Physics definition of work?

Is what you’re doing now work?

Work involves ForceWork involves Force

The more force that is applied the more work is done.

Work Involves DistanceWork Involves Distance

The more distance traveled the more work is done.

So Work Is…So Work Is…

Force acting upon an object in the direction the object moves.

Two conditions must be met for work to be done:Two conditions must be met for work to be done:

1. The object MUST move.

2. A force must act on the object in the direction the object moves.

No move, no work.

Is doing pull-ups?Is doing pull-ups?

                                         

Is Sitting in your Desk?Is Sitting in your Desk?

Is pumping Gas?Is pumping Gas?

Is Carrying a box?Is Carrying a box?

Direction of movement

Applied force

Once the box is moving, no force is necessary to keep it moving!

What two conditions must be met?What two conditions must be met?

So…

W = F * d

Let Practice!Let Practice!Rita mows lawns on the weekends. If she uses 15 N of force to move a lawn mower a distance of 10 meters, how much work does Rita do?

W = F * d

W = (15N) * (10m)

What are the units?

N * m or Joule (J)W = 150

So what’s this energy buinsess and how does work fit in?

So what’s this energy buinsess and how does work fit in?Energy- is the ability to do work

PotentialKinetic

Potential EnergyPotential Energy

The energy an object has by virtue of its position in a gravitational field.The higher an object above the ground the more potential energy.

Kinetic EnergyKinetic Energy Energy of Motion

We Simply Have to Remember…We Simply Have to Remember…

Energy is conserved You can’t make it You can’t destroy it You can only change it from one form to another!

This Is The “No Free Lunch” PrincipleThis Is The “No Free Lunch” Principle

You never get somthin’ fer nuthin’

$$$$$$$$$$$$$$$$$ This is also true for

Energy

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