An electric elevator with a motor at the top has a multistrand cable weighing 3.5 lb/ft. when the car is at the first floor, 160 ft of cable are paid out, and effectively 0 ft are out when the car is at the top floor. how much work does the motor do just lifting the cable when it takes the car from the first floor to the top?

0.11 m/s and 0.28 m/s should be correct

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