Assume that the small-massed particle is
and the heavier mass particle is
.
Now, by momentum conservation and energy conservation:


Now, there are 2 solutions but, one of them is useless to this question's main point so I excluded that point. Ask me in the comments if you want the excluded solution too.

So now, we see that
and
. So therefore, the smaller mass recoils out.
Hope this helps you!
Bye!
Answer:
Explanation:
The energy of a photon is given by the equation
, where h is the <em>Planck constant</em> and f the frequency of the photon. Thus, N photons of frequency f will give an energy of
.
We also know that frequency and wavelength are related by
, so we have
, where c is the <em>speed of light</em>.
We will want the number of photons, so we can write

We need to know then how much energy do we have to calculate N. The equation of power is
, so for the power we have and considering 1 second we can calculate the total energy, and then only consider the 4% of it which will produce light, or better said, the N photons, which means it will be
.
Putting this paragraph in equations:
.
And then we can substitute everything in our equation for number of photons, in S.I. and getting the values of constants from tables:

Answer: 114 km/h
Explanation:
The formula for determining average speed is expressed as
Average speed = total distance/total time
The car travels 85 km in the first half hour of a trip. The car continues to travel for 2 more hours and travels 200 km. It means that the total distance that the car travels is
85 + 200 = 285 km
The total time spent by the car is
0.5 + 2 = 2.5 hours
Therefore,
Average speed = 285/2.5 = 114 km/h
Well, with the light spectrum there technically is no middle color. Both green and yellow meet up in the middle at 560 nm (wavelength interval) and 540 THz (frequency interval).