What if the frequency is now increased to f = 69 hz, and we want to keep the impedance unchanged? (a) what new resistance should we use to achieve this goal? r = ω (b) what is the phase angle (in degrees) between the current and the voltage now? ϕ = ° (c) find the maximum voltages across each element.

hello there!

your answer is a “generator”

a generator does not create energy but instead it transforms it.

it’s basically a motor working in reverse.

you'd use the equation that establishes a relationship between  energy  and  wavelength, which looks like this

e=h⋅cλ, where

λ  - the wavelength of the photon; c  - the speed of light, usually given as  3⋅108m/s; h  -  planck's constant, equal to  6.626⋅10−34j s

plug the value you were given for the energy of the photon in the above equation to get the wavelength

e=h⋅cλ⇒λ=h⋅ce

λ=6.626⋅10−34js⋅3⋅108ms−1.257⋅10−24j=1.581⋅10−1m