MORE SIMPLE MACHINES

WHEEL AND AXLE What is it? 2 circular or cylindrical objects fastened together that rotate about a common axis How it works Smaller input force applied on the wheel, exerts a larger output force on the axle Increases your force, so you must exert your force over a long distance To increase distance, exert force on the axle

IMA OF A WHEEL AND AXLE IMA = Radius of Wheel divided by the radius of the axle IMA = Radius of Wheel / Radius of Axle

WRITE YOUR THOUGHTS To increase IMA, would you increase the radius of the wheel or the axle?

PULLEY What is it? A grooved wheel with a rope or cable wrapped around it How it works Pull on end of the rope (Input Force), the other ends pulls a load (Output Force) Pulleys can decrease input force Pulleys can change the direction you apply force

TYPES OF PULLEYS Fixed Pulley = attached to a structure Moveable Pulley = attached to a load Block and Tackle = a combination of fixed and moveable pulleys

IMA OF A PULLEY IMA = number of sections of rope that support the object or load What is the IMA of a fixed pulley? A moveable pulley?

SIMPLE MACHINES IN THE BODY Most of the machines in your body are levers Tendons and muscles pull bones Joints act as fulcrums Sharp front teeth (Incisors) act as wedges

COMPOUND MACHINES Many Machines consist of combinations of simple machines Compound Machine: a machine that utilizes 2 or more simple machines IMA = total IMA of all machines that make up the compound machine