2. Simple Machines -Levers-Pulleys -Inclined Planes -Wheel & Axel -Wedges-Screws

3. Activity 1: “Doing Work” Force- a push or a pull on an object. Force- a push or a pull on an object. Newton- the international unit of force Newton- the international unit of force Work- the result of a force moving an object over a distance. Work=Force x distance Work- the result of a force moving an object over a distance. Work=Force x distance Joule- unit used to measure work Joule- unit used to measure work

4. Question??? How many joules of work will be required to move seventy-five books from the floor to a shelf 2 meters high, if each book requires a force of 2 newtons to lift? How many joules of work will be required to move seventy-five books from the floor to a shelf 2 meters high, if each book requires a force of 2 newtons to lift? Answer: 2 newtons x 2 meters x 75 books = 300 joules Answer: 2 newtons x 2 meters x 75 books = 300 joules..\..\Video Clips\Science Video Clips\Force Man.flv..\..\Video Clips\Science Video Clips\Force Man.flv..\..\Video Clips\Science Video Clips\Force Man.flv..\..\Video Clips\Science Video Clips\Force Man.flv

5. Activity 2: “Levers” Machine- any tool that makes it easier to do work. Machine- any tool that makes it easier to do work. Simple Machines- require only the use of a human or animal to perform work…..they have few or no moving parts. Simple Machines- require only the use of a human or animal to perform work…..they have few or no moving parts. Six types of simple machines: Six types of simple machines: –lever-inclined plane –pulley-wedge –wheel and axle-screw

6. Levers Lever – a rigid bar that pivots on a fixed point called a fulcrum. Lever – a rigid bar that pivots on a fixed point called a fulcrum. All levers have 4 main components: All levers have 4 main components: 1. arm- a beam or bar 2. fulcrum- the pivot point on lever 3. load- the object to be moved 4. effort- the force needed to move the load

7. Activity 3: “Friction” Friction- resistance and heat created when two surfaces rub together. W= F x d (Work = Force x distance) Lubricant- substance that reduces friction.

8. Activity 4: “Inventing the Wheel” Other than using a lubricant, how can we reduce the amount of friction resulting from one surface passing over another? Other than using a lubricant, how can we reduce the amount of friction resulting from one surface passing over another? Wheel- a wheel is a disk that turns around an axis and transfers force to and from an axle. Wheel- a wheel is a disk that turns around an axis and transfers force to and from an axle.

9. Activity 5: “Wheel & Axle” Axle- a shaft to which one or more wheels is attached. Axle- a shaft to which one or more wheels is attached. W= F x d (Work = Force x distance W= F x d (Work = Force x distance

10. Activity 6: :Tractor Traction” Traction-(also called moving friction)-the amount of contact between two surfaces necessary for one surface to travel across the other. Traction-(also called moving friction)-the amount of contact between two surfaces necessary for one surface to travel across the other.