The magnetic force on a charged particle is in the direction of its velocity if: A. it is moving opposite to the direction of the field B. it is moving perpendicular to the field C. it is moving in some other direction D. never E. it is moving in the direction of the field

he . if i may ask what i your question exactly?

explanation:

friction

explanation:

they us to move forward and backwards

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