Work and Machines

WORK Is force through a distance Eef ya work ha’d you can Be strong like me!! Maybe Even Govana sum day!!!! Is force through a distance If force is applied to an object, and the object moves work has been done

No motion, no work. If a force is being applied to an object, it must move for work to be done

Calculating Work Work can be determined by the formula W = Force X Distance Ex: If it takes10N (newtons)to move an object 10m, 100 J(joules) of work was done W= 10N X 10m W = 100J

Machines Are devices that make work easier by changing the amount of force you exert, the distance which you exert the force, or change the direction of force applied

Input and Output Force The force applied to a machine is the input force, and the force exerted by the machine is the output force (resistance force)

Simple Machines There are six types of simple machines Inclined Plane Wedge Screw Lever Wheel and axle Pulley

Inclined Plane A flat slanted surface Allows you to apply force over a distance Ideal mechanical advantage is the length of plane divided by height of plane IMA= LOP/HOP IMA = 10/2 = 5 10 2

There is NO change in the amount of work done!!!!!! Inclined Plane Inclined planes allow you to exert force over a longer distance, making it seem easier to move the object. Input force is decreased. There is NO change in the amount of work done!!!!!!

Wedge Device thick at one end and tapers to a thin edge at the other Input force is transferred to the thin edge as an output force

There is NO change in the amount of work done!!!!!! Wedge Wedges allow you to multiply input force. Wedges are two inclined planes back to back that move through an object. The longer and thinner a wedge, the less input force is required to do the same amount of work. There is NO change in the amount of work done!!!!!!

Screw An inclined plane wrapped around a cylinder Input force is applied over a greater distance

There is NO change in the amount of work done!!!!!! Screw Screws allow you to exert input force over a longer distance, making the effort seem easier. Increased distance means less input force is required to do the same amount of work, with increased output force. Includes jar lids, faucets and bolts too. There is NO change in the amount of work done!!!!!!

Lever A rigid bar free to pivot, or rotate, about a fixed point Fulcrum- area a lever pivots Three types based on fulcrum, effort, and output IMA= Distance from fulcrum to input/distance to fulcrum and output IMA= D F-I/D F-O

Lever There is NO change in the amount of work done!!!!!! Levers can change the direction of the input force such as wheelbarrows, doors, and bottle openers. Levers can increase the distance such as rakes, fishing poles, shovels and baseball bats. Levers can multiply force such as with a paint can opener, pry bar, scissors, pliers and a seesaw. There is NO change in the amount of work done!!!!!!

Wheel and Axle Made of two circular or cylindrical objects attached to each other Larger object is wheel, and smaller the axle Wheel and axles multiply force, but force is exerted over a longer distance IMA= Radius of Wheel/Radius of axle

There is NO change in the amount of work done!!!!!! Wheel and Axle Wheel and axles allow you to multiply input force over a greater distance. There is NO change in the amount of work done!!!!!!

Pulley Grooved wheel with a rope, chain, or cable wrapped around it They change the amount and direction of the input force Fixed, movable, and pulley systems

There is NO change in the amount of work done!!!!!! Pulley Pulleys allow you to change the amount and direction of the input force. There is NO change in the amount of work done!!!!!!

Compound Machines A device that utilizes two or more simple machines IMA of each simple machine adds up to total IMA