Rayleigh's Oil Drop Flashcards
How can estimations be used?
Measurements such as height or mass. For height, humans are closest to 1m tall, which is 10^0m. Atoms have diameter 10^-15m. A book can be measured with a scale and divided by it’s page numbers to find the average page mass, but scales have poor resolution and there will be mass differences between the pages.
How is the experiment done?
Measure the diameter of an oil drop, and divide by 2 to find radius.
Place on still water and observe its spreading with flour, before measuring the diameter and dividing by two for it’s radius.
What is the volume of the drop, and what’s the volume of the patch?
Drop = 4/3 * pi * r^3 Patch = pi * R^2 * h (h is the diameter of an oil atom).
Where is the largest uncertainty?
Measuring the diameter, as the radius from this has to be cubed, and cannot be measured more precisely than +- 0.025mm for a radius between 0.5-1mm. Radius is cubed.
