Single Pulley Use and Application

1. The single pulley is one type of simple machine.

2. Construct a one-pulley system by attaching the single pulley to the edge of the lab table (picture a, below).

3. Attach the string to the load and tie two knots to secure it (picture b).

4. Feed the free end of the string over the top of the fixed pulley (picture b).

5. Place a meter stick vertically against the table leg so that you can read the distance that the load is being pulled (picture c).

6. If measuring the force required to lift the load, attach a spring scale to the free end of the string (picture c). Make sure that the spring scale is calibrated for use upside down as directed in Spring Scale Use and Operation.

7. Lift the load by following the steps below:

a. Begin with the bottom of the load even with the 1 cm mark on the meter stick.

b. If a spring scale is being used, raise the load by the desired distance by pulling on the loop at the bottom of the spring scale. If a spring scale is not being used, pull on the free end of the string (picture d).