# Formula: Oil Drop Experiment (Levitation Method)

## Electric charge

Unit
The charge of the oil droplet. The oil droplet carries a multiple of the elementary charge $$e$$.

## Distance

Unit
Distance between the two capacitor plates.

## Voltage

Unit
Voltage is applied between the two capacitor plates to accelerate charged oil droplets in the electric field.

## Viscosity

Unit
Viscosity $$\eta$$ (pronounced: Eta) is a property of a fluid (liquid or gas) and describes how difficult it is to move a body through this fluid.

Liquid Viscosity $$\eta$$
Olive oil$$108 \cdot 10^{-3} \, \frac{\mathrm{kg}}{ \mathrm{m}\cdot \mathrm{s} }$$
Honey$$10\,000 \cdot 10^{-3} \, \frac{\mathrm{kg}}{ \mathrm{m}\cdot \mathrm{s} }$$
Glycerin$$1500 \cdot 10^{-3} \, \frac{\mathrm{kg}}{ \mathrm{m}\cdot \mathrm{s} }$$
Water$$1.008 \cdot 10^{-3} \, \frac{\mathrm{kg}}{ \mathrm{m}\cdot \mathrm{s} }$$
Tar$$100\,000 \cdot 10^{-3} \, \frac{\mathrm{kg}}{ \mathrm{m}\cdot \mathrm{s} }$$
Viscosity of some liquids.

## Falling velocity

Unit
Terminal velocity at which the oil droplet sinks downwards inside the plate capacitor.

## Oil density

Unit
Oil density specifies the mass of the oil droplet per volume.

## Medium density

Unit
Density (mass per volume) of the medium between the capacitor plates.

## Gravitational acceleration

Unit
Gravitational acceleration is the acceleration acting on oil droplets to the bottom. It has the value: $$g = 9.8 \, \frac{\mathrm m}{\mathrm{s}^2}$$.