Energy Concepts and Simple Machines

1. Work

1.1. Work occurs when an outside force causes an object to move.

1.2. Work = Force * Distance (joules)

1.3. Examples: when you kick a soccer ball and it goes into the goal

1.4. Simple machines do work when they cause an object to move.

2. Mechanical Advantage

2.1. Mechanical advantage tells us how much a machine multiplies a force of increases the distance.

2.2. Actual MA = output force / input force

2.3. Ideal MA = input distance / output distance

2.4. Examples: how much easier it is to bring a box up a ramp rather than climbing up stairs.

2.5. Mechanical advantage can tell us what simple machine will be the most effective to use for a specific task.

3. 2nd Class Levers

3.1. Examples: wheelbarrow

4. Inclined Planes

4.1. A simple machine that makes it easier to move objects up of down in elevation rather that stairs.

4.2. Example: wheelchair entrance, ramp onto a moving van

4.3. Input distance-length of ramp

4.4. Output distance-height of ramp

5. Screw

5.1. Is used to hold things together

5.2. Examples: a screw

6. Wheel and Axle

6.1. Helps you get from place to place on public transportation.

6.2. Examples: wheels on car or bus

7. Power

7.1. Power is the rate at which work get done.

7.2. Power = Work / Time taken (Watts)

7.3. Examples: how fast you carry a box into the house

7.4. Simple machines have a lot of power when they can get jobs done efficiently

8. 1st Class Levers

8.1. Examples: screwdriver

9. 3rd Class Levers

9.1. Examples: baseball bat, hockey stick, golf club

10. Wedge

10.1. You can use a wedge to split something apart.

10.2. Examples: axe

11. Pulley

11.1. Helps move heavy things to a higher elevation easily.

11.2. Examples: a pulley