I think your talking about refraction and if so the first medium it existed in before entering the second usually has the higher speed especially it the first medium is less denser than the second
The Coulomb's force acting between two charges is

where

is the Coulomb's constant, q1 and q2 the two charges, and r the distance between them.
Using

, we can find the distance between the two charges when the force is F=19.2 N:
D. Collect more evidence and try to convince the other scientist
Answer:
Explanation:
According to heisenberg uncertainty Principle
Δx Δp ≥ h / 4π , where Δx is uncertainty in position , Δp is uncertainty in momentum .
Given
Δx = 1 nm
Δp ≥ h /1nm x 4π
≥ 6.6 x 10⁻³⁴ / 10⁻⁹ x 4 π
≥ . 5254 x ⁻²⁵
h / λ ≥ . 5254 x ⁻²⁵
6.6 x 10⁻³⁴ /. 5254 x ⁻²⁵ ≥ λ
12.56 x 10⁻⁹ ≥ λ
longest wave length = 12.56 n m