1. Work notes: In science, ‘work’ has a specific meaning
Work is ONLY done when a causes a change in the of an object in the of the applied force
i.e.

2. THINK!
What’s the difference between doing work and not doing work (in a scientific sense)?
How do you think you might need to know in order to calculate ‘work’? (Hint: what HAS to happen for work to be done?)

3. If to do work you must apply that changes the of an object, in a
of an applied force …
Think back: what is “The change of position in a direction”?

4. WORK EQUATION: W = FΔx Work = Work Equation W = work, F = force,
Δx = displacement
W = FΔx

5. is measured in . 1 J = 1 N•m = 1 kg•m2/s2
1 joule is roughly equal to the
energy required to lift a small
apple 1 meter
*N measures force/weight
*m measures mass...
To find weight in N, need to use Fg=mg
James Prescott Joule

6. Practice!
A crane uses an average force of 5200 N to lift a crate 25 m. How much work does the crane do on the girder?

7. An apple weighing 1N falls a distance of 1m
An apple weighing 1N falls a distance of 1m. How much work is done on the apple by the force of gravity?

8. Challenge
A mechanic uses a hydraulic life to raise a 1200 kg car 0.5 m off the ground. How much work does the lift do on the car?