Please help me I’m struggling :( When is a secondary source more helpful than a primary source?
A. When you want to know the exact data values
B. When you do not need to know the conclusion of the experiment
C. When you want to confirm the conclusion with your own
experiment
D. When you are not an expert in the field being studied in the
experiment

v=ir = 3x15 =45 v

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