Name ______Period ______Date ______
Mrs. Levin
Review Questions 3
Energy
1. What is energy? The ability to do work or cause change
2. Complete the table below on the two kinds of energy.
Type of energy / Description / ExamplePotential / Stored energy / Ball at top of building, water at top of waterfall
Pendulum at highest point
Energy stored in food
Kinetic / Energy in motion / Ball flying after being hit with bat, ball at lowest point after being dropped off building, water at bottom of waterfall
3. Explain how potential energy can change into kinetic energy in a pendulum or waterfall or fall:
At highest point it is potential energy
Potential changes to kinetic as it gains speed, at bottom it is all energy of motion and none is stored.
4. Complete the table on the 6 forms of energy. The first one is done for you.
Form of Energy / Description / ExamplesMechanical / Energy of moving parts / Person moving, pencil sharpener
Thermal / Heat energy / Hot coffee, radiator, heater
chemical / Energy in chemical reactions / Fire, chemical reaction, food, batteries
electrical / Energy of moving electrons / Electricity, lightning
electromagnetic / Radiant, light energy / Sunlight, lamp
nuclear / Energy in the nucleus of atoms / Nuclear power plant, stars
sound / Anything you hear- travels through gas, liquid, solid, does not travel in a vacuum / Bell, voice, music,
5. As a candle burns what energy change takes place? Chemical burning to heat and light energy
6. Label the energy conversions in an electric hairdryer:
Electrical (notice the plug) à mechanical (motor turning air blowing your hair) and thermal /heat
(Starting form of energy) (Form of energy produced) (Form of energy produced)
7. Label the energy conversions in
a battery operated flashlight:
chemical (battery)_ à ___electrical (wires)______electromagnetic (light)
8. What is a static electricity? Buildup of charge on an object
9. In both static electricity and magnetism, like charges or poles __repel____.
10. What is a magnetic field? Where is it strongest around a bar magnet?
Area around magnet where magnetic force is strongest – strongest at the poles.
______
______
11. What is electricity?
Flow of electrons, or charges
12. What is a renewable resource? Give some examples too. Energy source that can be replaced or not used up – examples are wind, solar, hydropower, biofuel
13. What are non-renewable energy sources: coal, oil, natural gas, nuclear
14. Series circuit – all attached in the same power source in the same line
15. Draw a diagram of a parallel circuit: each has their own pathway to the energy source.
Use the diagram below to answer the next two questions
16. Which switch will turn off only B? __7__
17. Which switch will turn off only D? __3____
18. What is a conductor: something that passes along, either electricity or heat
19. What is an insulator: something that does not pass along, either energy or heat
Motion, Forces, and Simple Machines
20. What is force? A push or a pull_
21. What is friction? Force that one surface exerts on another when two forces rub together – it depends on how hard they push and the surfaces.
22. What is acceleration? The change in velocity, it can be increasing speed, decreasing speed or changing direction.
23. What are some ways to reduce friction? Oil, wax, smooth surface, reduce haw hard the press together.
24. What are some ways to increase friction? Sand, roughen surface, more weight
25. What instrument is used to measure force? Spring scale
Newton’s Laws
26. What is inertia? The tendency of an object to resist change in motion (nobody likes change)
27. What is Newton’s first law of motion? An object in motion stays in motion and an object at rest stays at rest unless acted upon by an unbalanced force
28. What is the formula for Newton’s second law of motion?
F = __mass X acceleration
29. Newton’s second law of motion says if you have a bigger mass, you will need __bigger___ force to move it.
30. Newton’s second law of motion says if you have a bigger force, and the same mass, an object will move with greater__acceleration___.
31. According to Newton’s third law of motion, when a book pushes down on the desk, the desk ______pushes back with an equal and opposite force
HEAT
32. What is conduction? Heat moving by particles hitting or colliding with each other
33. What is convection? Heat moving by currents: particles in a liquid or gas heat up and spread apart becoming less dense, then rise, then cool and become more dense and sink
34. What is radiation? Heat moving in waves
35. How are molecules in a solid arranged? Tightly packed and vibrating
36. How are molecules in a liquid arranged? Not as tightly packed and sliding past each other
37. How are molecules in a gas arranged? Not packed at all, vibrating and whizzing around, bouncing off each other
WAVES
38. What type of energy is transferred by vibrational waves? Sound
39. What is a wavelength? The distance between one wave crest and the next
40. What happens when light is reflected? It bounces.
41. What happens when light is refracted? It bends or breaks (fracture – refraction.)