Aball has an electric charge of +1.5 × 10-9 coulombs. at what distance from the ball's center is the electric field strength equal to 5.8 × 105 newtons/coulomb?
(k = 9.0 × 109 newton·meter2/coulomb2)

0.2 × 10-2 meters
4.8 × 10-3 meters
3.0 × 10-2 meters
5.8 × 105 meters

i keep failing this quiz.

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