1. Simple Machines
Spring 2014

2. Simple Machines

3. Inclined Plane
A plane is a flat surface. When that plane is inclined, or slanted, it can help you move objects across distances and that's work! A common inclined plane is a ramp. Lifting a heavy box onto a loading dock is much easier if you slide the box up a ramp--a simple machine.

4. Wedge
You can use the edge of an inclined plane to push things apart. Then, the inclined plane is a wedge. So, a wedge is actually a kind of inclined plane. An axe blade is a wedge. Think of the edge of the blade. It's the edge of a smooth slanted surface.

5. Screw A screw an inclined plane wrapped around a cylinder.
A screw can convert a rotational force (torque) to a linear force and vice versa.

6. Lever
Any tool that pries something loose is a lever. A lever is a rigid bar that "pivots" (or turns) against a "fulcrum" (or a fixed point).

7. Wheel and Axle
It is two circular objects attached together about a common axis
Wheel is the large cylinder
Axle is the small cylinder

8. Pulley
In a pulley, a cord wraps around a wheel. As the wheel rotates, the cord moves in either direction. Now, attach a hook to the cord, and you can use the wheel's rotation to raise and lower objects.

9. Energy, Work, Power, & Machines
8.The mechanical advantage is the number of times a machine multiplies an effort force. Mechanical advantage can be calculated by the following equations:
AMA = Fr IMA = de
Fe dr
AMA = actual mechanical advantage (real life)
IMA = ideal mechanical advantage (pretend)
Fr = resistance force de = effort distance
Fe = effort force d r = resistance distance
9. The mechanical advantage of a pulley system is determined by counting the number of strands of rope that support the resistance force.

10. Energy, Work, Power, & Machines
10.Work input is always greater than work output due to friction.
Win= W out
Fe x de = Fr x d r
Win = work input (J)
W out = work output (J)
Fe = effort force (N)
de = effort distance (m)
Fr =force of the resistance (N)
d r=how far the resistance moved (m)

11. Energy, Work, Power, & Machines
11.Efficiency is a measure of how much of the work put into a machine is changed to work put out by the machine.
Efficiency is calculated using the following formula:
efficiency = W out x 100%
Win
efficiency = AMA x 100%
IMA

12. Efficiency of a Machine
12.The amount of work obtained from a machine is always less than the amount of work put into it. This is because work is lost to friction.
Efficiency = output work / input work x 100
Remember that
work = force x distance

13. Energy, Work, Power, & Machines
13. Compound machines consist of two or more simple machines. A pencil sharpener is an example of a compound machine.