7th Grade

Unit 6: Forces and Motion

Lesson 3: Simple Machines

Vocabulary of Instruction:

Efficiency• Is the balance

between the form of an object and its function.

Effort• Is the force

applied to an object in order to get it to move.

Fulcrum• Is the place upon

which a lever pivots ... the point that it swivels around... the object that it rocks up and down on, or back and forth around.

Inclined Plane• Is a simple

machine or mechanical device which reduces the effort needed to raise an object by increasing the distance that it moves.

Input• Is the place

where the power is entered into the system.

Joule• Is a metric

system unit used to measure energy.

Lever• Is a simple

machine in the form of a plank or bar that pivots on a fulcrum.

Load• Is an object

or something that must be moved or supported.

Mechanical Advantage

• Is the upper hand you gain when you use a mechanical device or machine to help you multiply the amount of force you can transmit.

Newton• Is a unit used to measure force.

Output• Is the point

where the power comes out of a system.

Pulley• Is a simple

machine in the form of a wheel with a groove around the edge.

Resistance • Is the tendency of a material to resist

electric current passing through it or a force that opposes motion.

Screw• Is a simple

machine in the form an inclined plane consisting of a spirally threaded cylindrical rod.

Wedge• Is a simple

machine in the form of an inclined plane.

W = F x d• The work done

(W) is equal to the applied force (F) multiplied by the distance (D) the object travels.

Wheel and Axle • Is a simple machine

comprised of a wheel attached concentrically to a drum so that a rope will wind and unwind alternately from the wheel to the drum creating mechanical advantage

Work• Is an effort

that causes motion or makes up a product.