Objective:
To be able to measure how much work pulleys save us.

Materials: Ringstand With Ring, String (about 1.3meters), Weight, 4 Single Pulleys, Newton Spring Scale.

Directions:

1. Read all insturctions before you begin the lab experiment.


2. Tie a loop into each end of the string so that the pulleys can be hooked to the string.


3. Weigh the metal weight using only the Newton meter. Enter this amount into the Weight column of the data table.


4. Assemble the single fixed pulley as shown in figure 1. Measure the amount of effort needed to lift the weight. Enter this amount into the data table.


5. Assemble the single movable pulley as shown in figure 2. Measure the amount of effort needed to lift the weight. Enter this amount into the data table.


6. Assemble each of the other three arrangements and record the data into the data table.


7. Calculate the mechanical advantage (M.A.) for each pulley arrangement and record these numbers in the data table.

Questions:

1. Using the diagrams calculate the MA of figures 3, 4 and 5.









2. Was there a difference in the mechanical advantages that you calculated for the single fixed pulley and the single movable pulley? If so, why was there a difference?









3. As you added pulleys to the system, what happened to the amount of effort need to raise the mass?









4. Look carefully at the string pattern around the pulleys. Find the relationship between the pattern and the MA. Using only 4 pulleys, draw an arrangment of pulleys that has a MA of 5.


















5. When using a simple machine, you use less force. What do you have to do more of in exchange?