What is the efficiency of a ramp if you do 400 J of work to push a 60 N box up the ramp until it is 3.0 m above the ground?

float.

archimedes' principle

denser than water sinks in water.

denser than mercury would sink in it

because if the tool that you are using is not balanced it there would be false 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