C is the right one i think
The doppler effect is when waves’ wavelengths get squished when the source is moving toward you or stretched when the source is moving away from you. it can be observed with sound waves but not light waves because the speed of light is just too fast, meaning that we can’t move toward or away fast enough. (also some stuff with relativity).
What textbook is it though.....?
Answer:
10.95 minute
Explanation:
V = 120 V, I = 2 A, m = 0.489 kg, c = 4186 J/kgC, T1 = 23 C , T2 = 100 C
Let time be the t.
Heat energy is equal to electrical energy
m x c (T2 - T1) = V x I x t
0.489 x 4186 x (100 - 23) = 120 x 2 x t
t = 656.73 second
t = 10.95 minute