Write down two separate equations for Newton’s second law with static friction: one for forces pointing along the track and one for forces pointing perpendicular to the track. Do some forces appear in only one of the Newton’s law equations? For forces that have some component in both, make sure you break down those force vectors correctly in the equation.

the amount of current in the coil

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