A0.100–kilogram white ball moving with a velocity of 5 meters/second along the positive x–axis hits a stationary blue ball of the same mass. energy is not necessarily conserved, but momentum is. after the collision, the white ball moves off at an angle of 20° with respect to the positive x–axis and at a velocity 3.5 meters/second. the blue ball moves at an angle of –35° and a velocity of 2.1 meters/second. what is the final y–momentum of the system?

0

Explanation:

It is given that in the given system, the energy is not necessarily conserved but momentum is conserved.

This means that the initial momentum is equal to the final momentum. The initial momentum in the y-axis is zero as the ball is moving in the x-axis direction. Hence, the final momentum in the y-axis direction would be zero.

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