1. A LOOK AT THE NATURE OF ENERGY Force and Motion

2. What is Force? A force is a push or pull. A force may give energy to an object, creating motion, stopping motion, or changing its direction. Balanced forces are opposite in direction and equal in size. When forces are balanced, there is no change in motion. Unbalanced forces cause a change in motion.

3. Balanced and Unbalanced Forces

4. Friction Friction is a force that opposes motion. The three kinds of friction are sliding, rolling, and fluid friction.

5. Gravity Gravity is a force of attraction that exists between all objects in the universe. The size of the force of gravity depends on the masses of the two objects and the distance between them.

6. Impact of Mass on Gravity The size of the gravitational pull between objects depends on the masses of the objects. The larger the mass, the greater the gravitational pull. Even our own bodies have gravity. The Earth's gravity is far stronger than our own so we don't notice the gravity our bodies possess.

7. Nature of Energy Energy is the ability to do work. Energy can appear in many forms:  Mechanical  Heat  Chemical  Electromagnetic  Nuclear

8. Potential Energy Energy that an object has due to its shape or position is called potential energy. The potential energy that an object has is due to its height above the Earth’s surface.

9. Kinetic Energy Energy that an object has due to its motion is called kinetic energy. The heavier a thing is and the faster it moves the more kinetic energy it has.

10. Potential and Kinetic Energy Examples

11. Law of Conservation of Energy The law of conservation of energy states that energy can neither be created nor destroyed by ordinary means. When we use energy, it doesn’t disappear. We change it from one form of energy into another.

12. Measuring Motion Motion involves a change in position during a certain amount of time. The rate at which an object moves is speed. Any object that is changing its position has speed. Speed that does not change is called constant speed.

13. Velocity and Acceleration Speed only describes how fast an object is moving, whereas velocity gives both how fast and in what direction the object is moving. Acceleration is the rate of change in velocity. An object speed up is positive acceleration. An object slowing down is negative deceleration.

14. Momentum Momentum describes how strong a moving thing is. Things that aren't moving have no momentum. Moving things have less momentum if they are light or moving slowly, and more momentum if they are heavy or moving fast.

15. Force and Motion Games/Websites http://www.gamequarium.com/forcesandmotion.html http://phet.colorado.edu/en/simulation/forces-and-motion-basics http://www.bbc.co.uk/schools/scienceclips/ages/6_7/forces_movement.shtml http://sciencegames.4you4free.com/force_motion_gravity.html http://studyjams.scholastic.com/studyjams/jams/science/forces-and- motion/force-and-motion.htm http://studyjams.scholastic.com/studyjams/jams/science/forces-and- motion/force-and-motion.htm http://studyjams.scholastic.com/studyjams/jams/science/forces-and- motion/fgravity-and-inertia.htm http://studyjams.scholastic.com/studyjams/jams/science/forces-and- motion/fgravity-and-inertia.htm http://studyjams.scholastic.com/studyjams/jams/science/forces-and- motion/inertia.htm http://studyjams.scholastic.com/studyjams/jams/science/forces-and- motion/inertia.htm http://studyjams.scholastic.com/studyjams/jams/science/forces-and- motion/acceleration.htm http://studyjams.scholastic.com/studyjams/jams/science/forces-and- motion/acceleration.htm http://studyjams.scholastic.com/studyjams/jams/science/forces-and- motion/action-and-reaction.htm http://studyjams.scholastic.com/studyjams/jams/science/forces-and- motion/action-and-reaction.htm