Welcome Back Minions!!! Warm up on the board…

Review Question What defines a machine? – 1) A device that allows you to do work in a way that is easier. – 2) Something with a motor. – 3) Anything you hold. – 4) All the above.

Review Question What is an “input force”? – 1) Something that fits inside a machine. – 2) Something that stores energy. – 3) The force exerted on a machine. – 4) All of the above.

Review Question What is an “output force”? – 1) Force that fits on the outside of a machine. – 2) Force a machine exerts on an object. – 3) How far a machine is thrown. – 4) None of the above.

Review Question In what way can a machine make work easier? – 1) Change force – 2) Change distance – 3) Change direction – 4) All of the above

Review Question How can you tell if a machine is efficient? – 1) It says so on the label. – 2) The closer to 0% the better the efficiency. – 3) You feel resistance when using the machine. – 4) The closer to 100% efficiency the more efficient the machine is.

Simple Machines… 6 types of “Simple Machines” – Inclined Plane – Wedge – Levers (3 classes) – Screw – Wheel & Axle – Pulley (3 classes)

Effort & Load Effort – Force applied to an object. Load – The opposition to applied force, such as a weight to be carried or moved.

Inclined Plane Where do you think you have seen an inclined plane before?

Inclined Plane What is an inclined Plane? – Flat, sloped surface. Input force – Push/pull item Output force – Lifting object

Inclined Plane Mechanical Advantage Ideal Mechanical Advantage = Length of Incline ÷ Height of Incline The longer the ramp, the less force needed!

Wedge Where do you think you have seen a wedge before?

Wedge What is a wedge? – A device that is thick on one edge and tapers to a thin edge at the other end. It is actually one incline planes or even two incline planes back-to- back.

Wedge Mechanical Advantage The longer and thinner the wedge is, the less force needed!

Review What is the definition of an “effort”? – 1) Force applied on an object. – 2) Force applied on the user. – 3) The opposition to a force. – 4) None of the above.

Review What is the definition of the “load”? – 1) Force applied on an object. – 2) Force applied on the user. – 3) The opposition to a force. – 4) None of the above.

Review What is an inclined plane? – 1) A wheel and axle used to lift or lower. – 2) A flat, sloped surface. – 3) A means to pull objects apart – 4) None of the above

Review What gives an inclined plane a better mechanical advantage? – 1) The shorter the incline the less force needed. – 2) The longer the incline the more force needed. – 3) Both 1 and 2. – 4) The longer the incline, the less force needed.

Review What is a wedge? – 1) Flat, sloped surface. – 2) Two back-to-back inclined planes. – 3) A device that is thick on one edge and tapers to a thin edge at the other end. – 4) All of the above.

HOMEWORK!!! Typed, not handwritten. List 5 incline planes and 5 wedges around the house. – Tell me what makes it an inclined plane or a wedge. Due tomorrow. (Tuesday, March, 12 th, 2013)