A person's center of mass is easily found by having the person lie on a reaction board. A horizontal, 2.7-mm-long, 6.1 kgkg reaction board is supported only at the ends, with one end resting on a scale and the other on a pivot. A 65 kgkg woman lies on the reaction board with her feet over the pivot. The scale reads 28 kgkg . Part A What is the distance from the woman's feet to her center of mass

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