Presentation on theme: "Simple machine A simple device or invention for altering the magnitude or direction of a force. The six basic types are the lever, wheel and axle, pulley,"— Presentation transcript:
1 simple machineA simple device or invention for altering the magnitude or direction of a force.The six basic types are the lever, wheel and axle, pulley, screw, wedge, and inclined plane.
2 effort forceTo determine the mechanical efficiency of a machine, you need to determine the output force and the effort force, or the force you exert on the machine to cause it to do its work.
3 resistance forceresistance force is the force which an effort force must overcome in order to do work on an object via a simple machine.
4 pulleyA machine consisting of a wheel over which a pulled rope or chain runs to change thedirection of the pull used for lifting a load.
5 single pulley systemA pulley is a grooved wheel intended for use with a rope, cable or other flexible fiber. The rope is placed around one side of the pulley to change the direction of the force applied.
6 double pulley systemSystem consisting of two pulleys with a rope running around them to lift a load. Using two or more pulleys reduces the amount of effort needed.
7 What is a pulley?A pulley is a simple machine with a wheel over which a belt, cable, chain, or rope runs. Pulleys are used to lift and pull things. A simple pulley is connected to a load at one end and a person or other device at the other end to pull the rope or chain. The rope runs over the wheel, allowing the load to be lifted or moved.
8 How do elevators work?A cable elevator actually uses a simple machine called a pulley to lift the elevator box up and down. A pulley is a simple machine with a wheel, over which runs a belt, cable, chain, or rope. In an elevator, the box that people ride in is encased in a tall elevator shaft. The top of the box is connected to steel ropes that are connected to a pulley, controlled by a motor.