if there is not a reaction
Answer:
The index of refraction of quartz for violet light is 1.47.
Explanation:
It is given that, a narrow beam of white light is incident on a sheet of quartz.
The beam disperses in the quartz, with red light at an angle,
wrt to the normal and violet light traveling at an angle of 
The index of refraction of quartz for red light is 1.45.
We need to find the index of refraction of quartz for violet light.
Using Snell's law of red light as follows :

Here,
is the refractive index of air
is the angle of incidence
We can find the value of angle of incidence as follows :

Now again using Snell's law for violet light as follows :

So, the index of refraction of quartz for violet light is 1.47.
Each elements emission spectrum is distinct because each element has a different set of electron energy levels. The emission lines correspond to the differences between various pairs of the many energy levels. The lines (photons) are emitted as electrons fall from higher energy orbitals to lower energies.
B. +Q, + W are the correct sign
Assuming g = 10, the weight of the sled is 720N.
If it takes 26.5N to just pull the sled, then the frictional force f is 26.5N in the opposite direction.
f = μ*720N
26.5N = μ*720N
μ = 26.5N/720N = 0.037 (2 s.f.)