Index of refraction can be calculated using the following formula:

where
in a vacuum and "n" is the index of refraction. So we must calculate our velocity by manipulating the index of refraction formula and isolate v and so:

We could go one by one and calculate the velocity or use logic. If you divide by a larger number the output will be a smaller number. Therefore, the answer would be n=1.62 is the slowest.

By that logic when n=1 light would travel the fastest of these four scenarios. The key thing to understand about these problems is that the speed of light slows down as it goes through a medium, in a vacuum it's 3 x 10^ 8 m/s but as it goes through say air or water light slows down.
Answer:
d = 23.75 m
The zebra has gone 23.75m after 5 seconds.
Corrected question;
A zebra starts from rest and accelerates at 1.9 m/s2. How far has the zebra gone after 5 seconds.
Explanation:
From the equation of motion;
d = vt + 0.5at^2 .........1
Where;
d = displacement
v = initial velocity = 0
t = time taken= 5 seconds
a = acceleration = 1.9 m/s^2
Substituting the given values into equation 1;
d = 0(5) + 0.5(1.9×5^2)
d = 0.5(1.9×5^2)
d = 23.75 m
The zebra has gone 23.75m after 5 seconds.
when a number of force acting on a body doesn't changes its motion it is called balanced force
When a substance is heated, the molecules begin to vibrate faster and the space between molecules increases. So it would be speeding up.
Answer:
v = 10 V and E = 2 10³ N/C
Explanation:
The electrical potentials and the electric field at one point are related by the expression
ΔV = - ∫ E. dS
Where the bold indicates vector quantities, E is the electric field and S is the line of displacement of the load, in general displacement is perpendicular to the equipotential lines, which reduces the product scales to the ordinary product.
If the potential difference is the most usual that is V = 10 V, the electric field is
s = 0.5 cm = 0.5 10⁻² m
E = ΔV / S
E = 10/0.5 10⁻²
E = 2 10³ N / C