Answer:
The electric force is 
Explanation:
From the question we are told that
The Bohr radius at ground state is 
The values of the distance between the proton and an electron 
The electric force is mathematically represented as

Where n and p are charges on a single electron and on a single proton which is mathematically represented as

and k is the coulomb's constant with a value

substituting values
![F = \frac{9*10^{9} * [(1.60*10^{-19} ]^2)}{(2.63 * 0.529 * 10^{-10})^2}](https://tex.z-dn.net/?f=F%20%3D%20%20%5Cfrac%7B9%2A10%5E%7B9%7D%20%2A%20%20%5B%281.60%2A10%5E%7B-19%7D%20%5D%5E2%29%7D%7B%282.63%20%2A%200.529%20%2A%2010%5E%7B-10%7D%29%5E2%7D)

Answer:
Consider frames X and Y:
If X sees Y moving to his right then Y must see X moving to his right.
If this is not true then one can choose one frame over the other ( a favored frame and this is not allowed)
Answer:
Impulse = change in momentum w bounce
There are 2 impulses acting. Recoil of the fan going the negative direction and the impulse of the air bouncing off the sail. The greater impulse will bounce so the direction will be to the right moving the craft.
BMI is a measure of body fat determined by ones Height, Weight, and Gender.