PLEASE HELP ANSWER ASAP two sound waves have the two respective frequencies f = 200Hz and f = 500Hz
Calculate: a) the number of vibrations made by each wave during 5s
b) their two respective wavelengths d and 'd
c) successively compare their two: heights, vibration numbers and wavelengths. interpret the results obtained

PLEASE HELP I DONT KNOW THIS AND WE GOT AN EXAM IN 1 HOUR​

Unpolarized light of intensity i_0=750w/m^2 is incident upon two polarizers. after passing through both polarizers the intensity is i_2=280w/m^2. (a) what is the intensity of the light after it passes through the first polarizer in w/m^2? (b) write an equation for the angle between the polarizers in terms of the initial (i_0) and final (i_2) intensities. (c) find the angle between the polarizers in degrees.