Here are the answers to your questions:
Question 1: Radio waves are used in
- Answer: radar guns.
Question 2: Gamma rays are used in
- Answer: killing cancer cells.
Question 3: Infrared waves are used in
- Answer: night vision goggles.
Question 4: The longer the wavelength,
- Answer: the lower the danger is of that wave.
Question 5: The higher the frequency,
- Answer: the more energy the wave has.
Feel free to ask if you have more questions or need further clarification!