Rosa Ruiz Diaz & Wanda Valdez Brooklyn College Fall 2008 Is a mechanical device that helps us do work by helping us move things easier, faster or father. A simple machine has few or no moving parts. Simple machines are grouped into six types: 1. Lever 2. 3. 4. 5. 6. Inclined Plane Wheel and Axle Screw Wedge Pulley Simple machines are tools that use energy to do work. Energy is the ability to do work. A rigid bar that rotates on a pivot called a fulcrum. All levers have four parts: 1. A rigid bar, called the arm. 2. The fulcrum, or support around which the arms pivot. 3. The load, which is the object to be moved. 4. The effort, or force that is applied to move the load. 1. First Class Lever. 2. Second Class Lever. 3. Third Class Lever. In a first class lever the fulcrum is in the middle and the load and effort is on either side. ●Think of a see-saw. ● In a second class lever the fulcrum is at the end, with the load in the middle. Think of a wheelbarrow. In a third class lever the fulcrum is again at the end, but the effort is in the middle Think of a pair of tweezers An inclined plane is a flat surface that is higher on one end Inclined planes make the work of moving things easier A wheel and axle is a simple machine made of a rod attached to the center of a wheel. A screw is an inclined plane wrapped around a shaft or cylinder. The inclined plane allows the screw to move itself when rotated. Two inclined planes joined back to back. Wedges are used to split things. A pulley is a circular lever that consists of a grooved wheel rotating about a hub. A pulley needs a rope, chain or belt around the groove to make it do work. It a combination of simple machines that work together. Do you think that you are ready to take a quiz on your filamentality website? Let’s see http://www.teachersdomain.org/collection/k12/sci.phys.energy.work/ http://www.youtube.com/watch?v=72zNEactb-k http://www.edheads.org/activities/simple-machines/ Or http://www.quia.com/quiz/110999.html?AP_rand=1051613213 http://www.kn.att.com/wired/fil/pages/listamazingwa1.html Inclined plane Screw Wheel and axel Pulley Wedge Inclined plane NSF North Mississippi GK-8 They help us do work. They make our lives easier. Let’s see how many times we use simple machines in our lives. 7 6 6 5 4 morning afternoon evening 3 2 1 1 0 0 blender 0 scissors bicycle sharpener Mikids.com. 2006. Simple Machines. Accessed 2 February 2006. http://www.mikids.com/Smachines. htm Wikepedia. Accessed 3 February 2006. http://en.wikipedia.org/wiki/Mechan icaladvantage