Answer:
n1 sin θ1 = n2 sin θ2 Snell's Law (θ1 is the angle of incidence)
sin θ2 = n1 / n2 * sin θ1
sin θ2 = 2.4 / 1.33 * sin θ1
sin θ2 = 1.80 * .407 = .734
θ2 = 47.2 deg
Answer:
20 hertz of frequency produced.
Explanation:

Here we will find frequency and period should be in second, here given: 0.05 seconds
using the formula:


It is know as smoke because if you cook food smoke will go up in the air and that makes vapor and also water from the ground it suck up