Movable Pulley

DEFINE:-

A movable pulley is a pulley that is free to move up and down, and is attached to a ceiling or other object by two lengths of the same rope. Examples of movable pulleys include construction cranes, modern elevators, and some types of weight lifting machines at the gym.

Materials:-

• 2 tall surfaces of the same height (tables, countertops, or a countertop and a table)
• 3 2”x4” wood planks, long enough to span the distance between the tall surfaces
• 4 fixed pulleys
• 2 movable pulleys
• Rope that fits the pulleys
• Screws
• Screwdriver or drill
• Toolbox with handle
• Tools, books, and other objects to add weight to the toolbox
• Scale

Procedure:-

1. Using the screws and your screwdriver or drill, attach one fixed pulley to a point slightly off-center on one of your 2”x4” plank.
2. Feed the rope through the pulley.
3. Feed one end of the rope through a moveable pulley.
4. Attach the end of the rope fed though the movable pulled to the 2x4 plank, about 1 foot away from the fixed pulley.
5. Set the wooden plank between two high surfaces so the pulleys are facing down. 
6. Attach the handle of the toolbox to the movable pulley.
7. Place different objects in the toolbox until it is heavy. Weigh the toolbox on the scale.
8. Pull down on the free end of the rope and lift the toolbox. Record your observations. How much can you lift with the assistance of the movable pulley ?

I hope you enjoy