1. Physics
Vocabulary

2. force
a push or pull that causes an object to move, stop, or change direction

3. friction
a force that slows or stops motion when two surfaces rub against each other

4. magnetism
the attraction of an object containing iron to a magnet

5. gravitation
the force that pulls all objects in the universe toward one another

6. balanced forces
forces acting on an object that are equal in size and opposite in direction, canceling each other out

7. unbalanced forces
forces that are not equal; when one force is greater than its opposite force, the object’s motion changes

8. energy
the ability to cause change in position or temperature

9. electric current
the constant flow of electrons from through a conductor

10. conductor
a material that conducts electricity easily

11. electric circuit
the path along which electricity can flow

12. insulator
a material that does not carry electricity

13. resistor
a material that resists the flow of electricity in some way

14. electromagnet
a temporary magnet made by passing electric current through a wire coiled around an iron bar

15. reflection
the light energy that bounces off objects

16. refraction
the bending of light rays when they pass through a substance

17. lens
a piece of clear material that bends, or refracts, light rays passing through it

18. temperature
the average kinetic energy of all the molecules in an object

19. Heat energy
the energy of moving particles in a substance

20. hydroelectric energy
electricity generated from the force of moving water

21. tidal energy
a form of hydroelectric energy that produces electricity from the rising and falling of tides

22. nuclear energy
the energy released when the nucleus of an atom is split apart

23. geothermal energy
heat from inside the Earth

24. solar energy
the energy of sunlight