Machines Whats the Advantage What is a machine

Machines What’s the Advantage?

What is a machine? A device that makes work easier by changing the size or direction of a force.

Using a Machine to do Work § Work you do on a machine is called work input (input force). § Work done by the machine on an object is called work output (output force). Remember…. Work=Force x Distance

Why Use a Machine? Machines do not increase the amount of work done because the work output is never greater than the work input. Machines allow force to be applied over a greater distance, which means that less force will be needed for the same amount of work. So…. same work, but less force!!!

Mechanical Advantage Some machines make work easier than others do because they can increase force more than other machines can. Mechanical advantage is the number of times the machine multiples force. Higher the MA=easier work

Formula for Mechanical Advantage MA= output force/input force Example: A grocer uses a handcart to lift a heavy stack of canned food. Suppose he applies an input force of 40 N to the handcart. The cart applies an output force of 320 N to the stack of canned food. What is the MA of the cart?

Six Common Simple Machines Ø Lever Ø Pulley Ø Wheel & Axle Ø Wedge Ø Inclined Plane Ø Screw All of these are used in everyday tasks to make the work of those tasks easier.

Foldable Instructions 1. 2. 3. § § § Glue or tape six foldable squares into your INB (2 per page). On the outside, label with the simple machine and glue/tape a colored picture of the machine. Inside…. . For the lever (p. 584)-1)define lever, 2)sketch the three classes of levers (Fig 1, 2, 3) labeling input, output, and fulcrum, and 3)give common examples of each class. For pulley (p. 586)-1)define pulley, 2)describe 3 types, and 3)give examples. For all others, 1) define and 2) give examples. wheel & axle (p. 587) inclined plane (p. 588) wedge (p. 589) screw (p. 589)

Foldable Instructions 1. 2. 3. 4. Cut out foldable. Tape/glue down on right side of notes. Color the simple machines. Inside each tab, 1) give the definition and 2) give examples of common types of each machine.