1. Force and Motion

2. Learning Target for the week:
I can demonstrate and calculate how unbalanced forces change the speed or direction of an object’s motion

3. Energy: The ability to do work
Energy: The ability to do work. Energy Transformation: any process of transforming one form of energy to another. Fossil fuels, solar radiation, or nuclear fuels can be converted into other energy such as electricity or heat.

4. Examples of energy transformation
Turning on a flashlight
___________to____________
Turning on the T.V.
___________to____________&_____________
Wood burning in a fireplace

5. Chemical Energy: (food) energy produced by the food we eat Electrical Energy: form of energy that consists of a flow of electric charges through a conductor Thermal (heat) Energy: total kinetic energy contained in all the particles of a substance

6. Mechanical Energy: energy an object has because of its motion or position Other types of energy: light, sound, nuclear 2 Types 1. Potential Energy: stored energy an object has because of its position or shape 2. Kinetic Energy: energy an object or particle has because it is moving.

7. Simple Machines

8. Machine: a device that makes work easier by providing some trade-off between the force applied and the distance over which the force is applied

10. Lever: long rigid bar that rests on and pivots around a support
Lever: long rigid bar that rests on and pivots around a support -Fulcrum: a point around which a lever turns Effort Arm: the distance between the effort force and the fulcrum Resistance Arm: the distance between the resistance force and the fulcrum

12. Pulley: simple machine consisting of one or more wheels with a rope wrapped around them; Ex: miniblinds, flag pole Inclined Plane-reduces effort required to lift an object to a required height; Ex: handicap ramp

13. Wedge- 2 inclined planes joined back to back, used to split things; Ex: Axe
Screw- inclined plane wrapped around a shaft or cylinder; Ex: bolt, spiral staircase

15. Motion of Objects

16. Mass: amount of matter in something measured in grams Motion: a change of the position of an object with respect to time

17. Equilibrium: when an object is motionless or is in motion at a constant velocity Balanced Force: occurs when an object’s motion does not change Unbalanced Force: occurs when the object’s motion changes.

18. Unbalanced force

19. 20 N   30 N

20. Inertia: the resistance that an object has to a change in its motion
Inertia: the resistance that an object has to a change in its motion. Force: a push or a pull on an object that causes a change in motion in the same direction

21. What is work?
In science, the word work has a different meaning than you may be familiar with.
Work- using a force to move an object a distance (when both the force and the motion of the object are in the same direction.)
Force
Motion

23. Work or Not?
(Man is now carrying the box walking)
Force
Motion

24. What’s work?
A scientist delivers a speech to an audience of his peers.
A body builder lifts 350 pounds above his head.
A mother carries her baby from room to room.
A father pushes a baby in a carriage.
A woman carries a 20 kg grocery bag to her car?

25. What’s work?
A scientist delivers a speech to an audience of his peers. No
A body builder lifts 350 pounds above his head. Yes
A mother carries her baby from room to room. No
A father pushes a baby in a carriage. Yes
A woman carries a 20 km grocery bag to her car? No

26. Gravity: the force that causes objects to fall to the ground Weight: the force of gravity on an object