1. Mechanical Advantage

2. Can be expressed as the ratio of: 1)the resistance force (i.e. the load) to the effort force required to move it 2)the distance traveled by the effort force to the distance traveled by the resistance force These calculated ratios allow designers to manipulate a design to change speed, distance, force, and function. Describes how much the device helps you, i.e. how much advantage do you get from using it?

3. A mechanical advantage of 4:1 tells us what about a mechanism? Effort force travels 4 times farther than the resistance force would have. Magnitude of Force: Distance Traveled by Forces: Effort force is 4 times less than the resistance force. In other words the work is 4x easier, or you can do 4x more.

4. One is the magic number If MA is greater than 1: less effort force but greater effort distance are required to overcome a given resistance force If MA is less than 1: greater effort force but less effort distance are required to overcome a given resistance force MA is never less than zero.

5. Theory-based calculation (i.e. design prediction) Used in efficiency and safety factor design calculations Frictional losses are not taken into consideration Ratio of force distances D E = Distance traveled by effort force D R = Distance traveled by resistance force

6. Inquiry-based calculation (i.e. you actually measure it) Used in efficiency calculations Frictional losses are taken into consideration Ratio of force magnitudes F E = Magnitude of effort force F R = Magnitude of resistance force

7. Can you think of a machine that has a mechanical advantage greater than 1?

8. Can you think of a machine that has a mechanical advantage less than 1?

9. The force applied on an object times the distance traveled by the object Initial position Final position Distance (d) Force (F) Work = Force * Distance = F*d *The force needed to overcome friction is not considered*

10. The product of the effort times the distance traveled will be the same regardless of the system mechanical advantage

11. Microsoft, Inc. (2008). Clip Art. Retrieved January 10, 2008, from http://office.microsoft.com/en-us/clipart/default.aspx