Hw 5.2.a 5.00-kg chunk of ice is sliding at 12.0 m/s on the floor of an ice-covered valley whenit collides with and sticks to another 5.00-kg chunk of ice that is initially at rest. since the valleyis icy, there is no friction. after the collision, how high above the valley floor will the combinedchunks go? (g= 9.8 m/s2)

The concept used to solve this problem is the conservation of momentum and the conservation of energy.

For conservation of the moment we have the definition:

Where,

m = Mass

= Initial velocity for object 1

= Final velocity

Replacing the values we have to,

By conservation of energy we know that the potential energy is equal to the kinetic energy then

Therefore after the collision the height when the combined chinks will go is 1.837m

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