A 200-kilogram wood crate is pushed across a wood floor How much force will be needed to move the box at a constant velocity of 0.5 m/s

100N

Explanation:

F = m x a

m = 200kg

a = 0.5m/s

F = 200 x 0.5

F = 100

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