Answer:
n=2.053
Explanation:
We will use Snell's Law defined as:

Where n values are indexes of refraction and
values are the angles in each medium. For vacuum, the index of refraction in n=1. With this we have enough information to state:

Solving for
yields:

Remember to use degrees for trigonometric functions instead of radians!
Answer:
a. 
b. 
Explanation:
The inertia can be find using
a.





now to find the torsion constant can use knowing the period of the balance
b.
T=0.5 s

Solve to K'


If the Earth didn't tilt then we wouldn't have seasons.
Force = mass*acceleration so
3.6*2.5 =9 Newtons