What is the terminal speed?

Question

A rain drop of mass 0.034 gram with a radius of 0.2 cm attains a terminal speed when the drag force is equal to its weight (W=mg). Give air density 1.21 kg/m^3, effective surface area of the drop can be treated as

A= π*r^2. Drag coefficient C=1.

Calculate the terminal speed.

Answer 1

Hi Muhammad B.,

C'mon, don't be clueless. Look up the drag equation. This is the age of information; even if your book didn't give it to you directly, Google will (173,000,000 entries)! It uses a multiplier, the density of the liquid, the drag coefficient, the area (cross-sectional) of the drop, and v^2. Copy it, plug in, you already know (or can figure) what mg is for the drop. Solve!

--Cheers, --Mr. d.