17. a
18. c
19. a
20. c
21. c
Answer:
transparent Prism
Explanation:
The device shown is a prism. It is used to study the refraction of light according with its wavelength as it transverses from a medium (air for example) to another (either glass, fluorite, plastic), and vice versa.
For that reason is also used to separate white light into its spectral wavelength components.
Answer:
Ensure each member of the audience can see and read the aid.
Explanation:
Answer:
W and X
Explanation:
When escaping a rip current, one should always walk to the side until you escape from the rip current. If you walk towards the shore, you have the ability to keep getting dragged toward the current, such as with X and Y.
