calculate the height from which a body is released from rest if its velocity just before hitting the ground is 30 metre per seconds

height is 45 metres

Explanation:

KE=PE

¹/²mv² = mgh

¹/²v² = gh

but v =30m/s

(30)² / 2 =10h

450=10h

h = 45m

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