Answer:
Upper disk rotates at a constant angular velocity. The velocity at any height from stationery disk, say at x metres
where v is tangential velocity at radius r from the centre of disk
The radial component of velocity is given as
The z component of velocity is also given as
W=0
Total velocity,
343 meters per second Is the answer
Answer:
Number of electrons, n = 6
Explanation:
Total charge in a single droplet, 
The measured charge of any single droplet, 
Let n is the number of excess electrons are contained within the drop. According to the quantization of charge :



n = 6
So, there are 6 electrons contained within the drop. Hence, this is the required solution.
1. Avogadro's hypothesis. Avogadro hypothesized that equal volumes of all gases (at the same pressure) will have the same number of molecules. From PV=nRT, we know that one mole of gas takes up 22.4 L
2. Mass number. The mass number is the sum of the protons and neutrons in the nucleus so Carbon 12 has an atomic number of 6 which indicates 6 protons, and a mass number of 12 so 12-6 = 6 neutrons.
3. Avogadro's number. Avogadro's number is the number of units in one mole of any substance, which has been defined as 6.02 x10^23
4. Isotopes are the different forms of a single element. They differ in neutrons. One example is Hydrogen which has three isotopes Protium, Deuterium, and Tritium.
5. Atomic mass. The mass of the atom is equal to the sum of the protons and the neutrons as electrons are so small their mass is negligible. This is not exactly the same as the mass number because this number takes into account the different isotopes
6. mole A mole has the same number of entities as 12 grams of carbon 12, it is expressed by Avogadro's number so 1 mole = 6.02 x10^23 atoms or molecules, etc
7. molar mass- the amount that one mole of substance weighs. For carbon 12, 12 grams has one mole of atoms by definition. So for carbon 12, the molar mass is 12 g/mol
I hope it's not too late, but here you go