2. Work
The amount of energy transferred by a force over a certain distance
Measured in joules
If an object doesn’t move a distance, no work was done
W=FxD

3. Work= Force multiplied by distance
How much work is done by a person who pushes a lawnmower with a force of 50N at a distance of 450m?
55,000 J of work is done to move a rock 25m. How much force was applied?

4. Simple Machines
-make work easier by changing the size or direction of a force
-you do work on the machine, the machine does work on something else
-Mechanical advantage is the number of times the machine multiplies your force.

5. Lever Made up of a bar that pivots on a fulcrum
Change in direction makes work easier

6. Wheel & Axle Wheel attached to an axle
Force is transferred from one to the other
Axle moves faster than the wheel making work easier

7. pulley A pulled rope over a wheel Changes the direction of the force
Increases the applied force making work easier

8. Inclined plane Flat surface raised at an angle like a ramp
Used for lifting heavy loads instead of straight up
The increased distance decreases the force required

9. Wedge Two inclined planes put together Two planes form a sharp edge
Used to push objects apart or cut
The thinner the wedge, the easier the work

10. Screw A spirally grooved cylinder
An inclined plane wrapped around a cylinder
The less distance between the threads, the easier the work

11. Compound machines
2 or more simple machines working together

12. Simple Machine Video

13. 1st class lever Fulcrum placed between the effort and load
Example: Seesaw

14. 2nd class lever Load in between the effort and the fulcrum
Example: Wheelbarrow

15. 3rd class lever Effort in between the load and the fulcrum
Example: Baseball bat

16. The mighty mathematics of a lever