1. Name __________________________________________ Date _________________ Period __________
Pulleys
Directions: Pulleys are simple machines that can change the direction of a force. When used in groups, they can also change the amount of force required to move a given mass. A common example is a construction crane. These cranes have a series of several pulleys which reduce the force – yet increase the distance – needed to move an object. That is why a relatively small engine or motor can move incredibly massive things like I-beams, cars, etc. It is your job today to explore exactly how pulleys can change the amount of force put in and taken out of a system.
1. How much force is exerted on the ground by a 1,000 g mass?
2. Using one pulley and a spring scale, measure the amount of force that 1,000 g of mass is exerting.
3. Add two or more pulleys and measure the amount of input force that it takes to suspend 1,000 g of mass.
4. By how much, if any, has the input force changed?
5. Add more pulleys, and find out how much the input force changes. What is happening to the distance required to move the mass?
6. What is the relationship between the number of pulleys added and the input force required?