1. Science Benchmark 3 Review Motion, Laws of Motion, Machines, Work, Power, Energy, Energy Transformations

2. Motion In order for there to be motion In order for there to be motion an object must move in relation to reference points an object must move in relation to reference points

3. Speed How much time it takes for an object to move a certain distance How much time it takes for an object to move a certain distance Formula v= d/t Formula v= d/t Measured in m/s or km/hr etc Measured in m/s or km/hr etc If you know both speed and direction then you know ---- If you know both speed and direction then you know ---- Velocity Velocity

4. Acceleration The RATE at which velocity CHANGES The RATE at which velocity CHANGES All these are acceleration : All these are acceleration : Going faster Going faster Going slower Going slower Turning Turning This is why planets are accelerating – they are in a constant turn to form their orbit. This is why planets are accelerating – they are in a constant turn to form their orbit.

5. Laws of Motion 1 st - inertia – objects want to keep doing what ever they are doing 1 st - inertia – objects want to keep doing what ever they are doing Books fly on floor when bus stops Books fly on floor when bus stops You move forward when your parents slam on the car brakes You move forward when your parents slam on the car brakes

6. Laws of Motion 2 nd – acceleration – f=ma 2 nd – acceleration – f=ma A runner speeds up at the end of a race A runner speeds up at the end of a race A car slows down because they ran out of gas A car slows down because they ran out of gas It takes more force to stop a bus than a bicycle It takes more force to stop a bus than a bicycle To change acceleration – lower mass or use more force To change acceleration – lower mass or use more force

7. Laws of Motion Remember : Remember : Mass is the amount of matter in an object Mass is the amount of matter in an object Weight is a measure of the pull of gravity on an object Weight is a measure of the pull of gravity on an object

8. Laws of Motion 3 rd – action and reaction – equal and opposite!! 3 rd – action and reaction – equal and opposite!! When you jump down hard on a trampoline you will go high in the air When you jump down hard on a trampoline you will go high in the air When a rocket is fired the gases push downward causing the rocket to go upward When a rocket is fired the gases push downward causing the rocket to go upward

9. Machines There are six simple machines: There are six simple machines: 1. Lever 1. Lever 1 st class 1 st class 2 nd class 2 nd class 3 rd class 3 rd class

10. Machines 2. wheel and axle 2. wheel and axle

11. Machines 3. wedge 3. wedge

12. Machines 4. screw 4. screw

13. Machines 5. inclined plane 5. inclined plane

14. Machines 6. pulley 6. pulley

15. Work Work is using a force to move an object in the direction of the force Work is using a force to move an object in the direction of the force Formula w=fd Formula w=fd Measured in joules (J) Measured in joules (J)

16. Power How much work is done in a certain period of time. How much work is done in a certain period of time. The faster something does work the more power it has!! (less time) The faster something does work the more power it has!! (less time) Formula P=w/t Formula P=w/t Measured in watts (w) Measured in watts (w)

17. Energy Energy is the ability to do work or to make a change. Energy is the ability to do work or to make a change. There are two main categories of energy: There are two main categories of energy: Potential Potential Kinetic Kinetic

18. Potential Energy Potential Energy is stored energy. Potential Energy is stored energy. Food roller coaster Food roller coaster

19. Kinetic Energy Kinetic Energy is energy of motion Kinetic Energy is energy of motion

20. Energy Transformations Energy is changed from one form to another but none can be created or destroyed! Energy is changed from one form to another but none can be created or destroyed! Match – chemical to thermal

21. Energy Transformations Food – chemical to mechanical

22. Energy Transformations Food – chemical to mechanical

23. Chemical Reactions Remember the only true proof that a chemical reaction has taken place is the formation of a new substance with new properties!!!

24. Chemical Formula 2Ca + O 2 2CaO Remember to count atoms to see if balanced! Reactants Product

25. Good Luck!!!! Read well !!!!