1. 1.Mouths are quiet. 2.Begin the quick review section of your notes. 3.Raise your hand if you need something.

2. 1.

3. 2.

4. Lesson 3.10 – UV and High Energy Waves

5. 1. Waves with higher energy = more damaging to living things. a. Higher energy waves = higher frequency and shorter wavelength.

6. Type of Wave DescriptionImpact on Life Ultraviolet (UV) Light  Higher energy than visible light  Can make certain substances glow.  Not visible to humans, but some animals can detect it.  Lots of exposure can cause sunburns, cell damage, and eventually skin cancer.  Can kill bacteria cells.

7. Type of Wave DescriptionImpact on Life X-Rays  High energy  Can travel through soft tissue like skin, but not through bone  Lots of exposure can damage cells and DNA specifically.  Used in medicine and airport security.

8. Type of Wave DescriptionImpact on Life Gamma Rays  Highest energy  Produced by the sun and other stars  Very damaging to cells and DNA.  Used to sterilize medical equipment by killing bacteria and viruses.

9. 3. While gamma rays and x-rays can damage healthy cells in humans, they can also be used by doctors to kill cancer cells.

10. Which waves are harmful to cells? Ultra-Violet Rays X-Rays Gamma Rays

11. Which waves can cause skin cancer? Ultraviolet Rays = UV Rays

12. WORK WITH US…NOT AHEAD OF US!

13. 1. Gamma rays have a shorter wavelength than x-ray waves. Compare the energy transferred by an x-ray to that transferred by a gamma ray. Gamma rays transfer more energy than x-rays because they have a higher frequency and thus transfer more energy.

14. 2. Visible light waves have a longer wavelength than x-ray waves. Compare the energy transferred by an x-ray to that transferred by a visible light wave. Visible light has a longer wavelength and thus a lower frequency so it transfers less energy.

15. 3. A wave is classified as a gamma ray. What is the range of possible wavelengths for this wave? The wavelengths of a gamma ray range from 10 -2 nm to 10 -6 nm.

16. 4. A wave is classified as an x-ray. What is the range of possible wavelengths for this wave? The wavelengths of an x-ray range from 10 nm to 10 -2 nm.

17. Do you know what that means?

18. 1.) AC stands for: Alternating current Current can be easily transformed from higher to lower voltage Current changes magnitude and direction in time

19. 2.) DC stands for: Direct current Current flows in one direction Used in batteries!

20. 3.) Which three types of electromagnetic waves are damaging to the human body?

21. 4.) Newton’s 1 st Law: Law of Inertia: “A body at rest tends to remain at rest, and a body in motion tends to remain in motion, unless acted upon by an unbalanced force

22. 5.) Newton’s 2 nd Law: Force = mass x acceleration

23. 6.) Newton’s 3 rd Law: Action-Reaction Law: for every action there is an opposite and equal reaction

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25. 8.

26. Additional topics: Applying Newton’s Three Laws Speed equation Velocity equation Acceleration equation

27. (5 Questions)

28. 1. Which of these describes a wave with the most energy? A. Low frequency, long wavelength B. Low frequency, short wavelength C. High frequency, long wavelength D. High frequency, short wavelength

29. 2. Which of these waves is the least dangerous to humans? A. UV light waves B. Gamma rays C. X-rays D. All three waves are equally dangerous.

30. 3. Which of the following waves is safe for humans to be exposed to? A. Gamma rays B. X-rays C. UV light waves D. Radio waves

31. 4. Which of these does NOT describe ways in which UV light waves, x-rays, and gamma rays can be used to help humans. A. Can be used to kill cancer cells. B. Can be used in medical imaging. C. Can be used to damage DNA, causing skin burns. D. Can be used to kill bacteria in supermarkets.

32. 5. Which of the electromagnetic waves below could be used to kill bacteria in a city’s water? A. Infrared light waves B. Radio waves C. Visible light waves D. Ultraviolet light waves