Bell Work: 2/13/12  First, rank the following words from 0-5 (0= you have never heard of this word & 5= you know the word VERY well). Second, explain what the following terms mean in your own words:  Machine  Simple machines  Work  Force  Work input/Work output  Lever  Pulley  Wheel & axle  Inclined plane  Wedge  Screws  Compound machine

 Differentiate between the six simple machines. (SPI )  Determine the amount of force needed to do work using different simple machines. (SPI )

1. Complete the 2-square vocabulary activity in the vocabulary section with your group. Do the “yours” side for the 12 bell work words/phrases. 2. Complete the scenarios with your group. Write the explanations on your next blank page in your scientist notebook. 3. When you are finished, raise your hands and I will check your work.  Work hard, smart, and QUICKLY!!!

YOURS:TEXTBOOK:  A machine is a device that makes work easier by changing the size or direction of a force.  Examples: wheelchair, scissors, chopsticks

YOURS:TEXTBOOK:  A machine or simple device without moving parts.  Examples: lever, pulley, wheel & axle, inclined plane, wedge, screw

YOURS:TEXTBOOK:  Work is the transfer of energy to an object by using a force that causes the object to move in the direction of the force.  Work is done on an object if two things happen: 1) the object moves as a force is applied, 2) the direction of the object’s motion is the same as the direction of the force.  Examples: pushing a ball up a hill

OR YES NOYESNO

YOURS:TEXTBOOK:  A push or a pull exerted on an object in order to change the motion of the object; force has size and direction.  Examples: people, bulldozer, static electricity

YOURS:TEXTBOOK:  Work input is the work done on the machine.  Work out put is the work done by the machine.  Examples: opening a paint can

YOURS:TEXTBOOK:  A lever is a simple machine that has a bar that pivots at a fixed point, called a fulcrum.  Examples: first-class lever (see saw), second-class lever (wheelbarrow or soda bottle opener), third- class lever (lifting weights or hammering a nail)

First-Class LeverSecond-Class LeverThird-Class Lever Elementary SchoolMiddle SchoolHigh School

YOURS:TEXTBOOK:  A simple machine that has a grooved wheel that holds a rope or a cable.  Examples: fixed, moveable, block and tackle

The pulley changes the direction of the force. Elevators make use of fixed pulleys. Movable pulleys do increase force, but they also increase the distance over which the input force must be exerted. A fixed pulley and a movable pulley are used together; the mechanical advantage of a block and tackle depends on the number of rope segments.

YOURS:TEXTBOOK:  A simple machine consisting of two circular objects of different sizes.  Examples: car’s wheel & axle, faucet

YOURS:TEXTBOOK:  A simple machine that is a straight, slanted surface; a ramp.  Examples: ramp or slide

YOURS:TEXTBOOK:  A simple machine that is made up of two inclined planes and that moves; often used for cutting.  Examples: knife, axe, door stop

YOURS:TEXTBOOK:  A simple machine that consists of an inclined plane wrapped around a cylinder.  Examples: screw, light bulb

YOURS:TEXTBOOK:  A machine made up of more than one simple machine.  Examples: manual can opener

Take Five…  Take five minutes with your group to discuss your list of simple machines that help make your life or work easier around the house, at school, or anywhere.  Add simple machines to your list that your group members had, but you didn’t.

 Fill out the chart as we go through the Simple Machines activity on the Edheads website.

3 simple machines and their functions 2 differences between simple and compound machines 1 word problem to use with the formula W=F x d