Page 391:
3. - Electomagnetic radiation is a form of energy made of electric and magnetic fields travelling in waves created by a disturbance
4. - a) 1. Radio waves.
2. Microwaves.
3. Infrared.
- b) 1. Radio waves are used for radio and television broadcasting.
2. Microwaves are commonly used in a microwave oven appliance to heat food.
3. Infrared waves are commonly used in remote controls such as a television remote.
5. - a) 1. Ultraviolet.
2. X-Ray.
3. Gamma.
- b) 1. Ultraviolet waves are used to disinfect drinking water.
2. X-Ray is commonly used for medical imaging under controlled environments.
3. Gamma rays are used to sterilize medical equipment.
7. - From highest to lowest frequency: - Violet, blue, green, yellow, orange, and red.
8. - a) Red has the longer wavelength.
- b) Blue has the higher frequency.
9. The audience members will see yellow where the spotlights overlap.
10. - a) Both radio waves and X-Rays similar in that they're both used in medical imaging and cannot pass through bone.
- b) X-Rays are harmful to humans while radio waves are not. Radio waves have the capability to reach great distances while X-Rays do not.
11. - a) Very short wavelength radiation poses more of a danger to human health.
- b) Very short wavelength radiation poses more of a danger because more energy is being transmitted over a short period of time than very short wavelength radiation where small amounts of energy are being transmitted over a longer period of time.
12. - a) In green light the balloon will appear red and green.
- b) In magenta light the balloon will appear red and blue.
13. This is a wise choice because the colour white reflects all colours of the colour spectrum.
Page 409:
1. - The ray model of light shows the path the light takes after it radiates off its source.
3. - Two properties of light you can show using a ray diagram is its frequency and name of wave.
4. It will illuminate, transmit light, and may also absorb light.
8. - A regular reflection is when light rays strike a smooth surface and reflect in the same direction, keeping parallel to the source. Diffuse reflection is when light rays reflect off a rough or uneven surface and reflect in scattered directions.
11. - You are able to see a basketball because it is illuminated by another light source and is reflected into our eyes.
12. Metal is a much more reflective material than wood therefore it would make a better reflector.
