To solve this problem it is necessary to apply the law of Malus which describes the change in the Intensity of Light when it crosses a polarized surface.
Mathematically the expression is given as

Where,
= Initial Intensity
I = Final Intensity after pass through the polarizer
= Angle between the polarizer and the light
Since it is sought to reduce the intensity by half the relationship between the two intensities will be given as

Using the Malus Law we have,





Angle with respect to maximum is 
0.0605J is your answer. Use the formula KE=1/2mv^2
Noble gases are not highly reactive
Answer:
See the explanation below.
Explanation:
The force is a vector therefore we can decompose the force into components x & y. as we need the horizontal component of the force, we must use the cosine function of the angle.
![F_{1x}=30.8*cos(20)\\F_{1x}=28.94[N]\\F_{2x}=34.3*cos(20)\\\\F_{2x}= 32.23[N]](https://tex.z-dn.net/?f=F_%7B1x%7D%3D30.8%2Acos%2820%29%5C%5CF_%7B1x%7D%3D28.94%5BN%5D%5C%5CF_%7B2x%7D%3D34.3%2Acos%2820%29%5C%5C%5C%5CF_%7B2x%7D%3D%2032.23%5BN%5D)