a .685 kg block is placed on spring with a force constant k. the block is pushed downward a distance x=0.487m compressing the spring from its euilibrium length l=2.23m. the block isthen released, and the spring shoots upward. after the release, the greatest height the block reaches above the table where the spring is mounted is 4.73 m. what is the value of k?

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