Find the terminal velocity of an 8.5-inch-diameter sphere weighing 16 lbf falling through the following fluids under the action of gravity: (a) the standard atmosphere at sea level; (b) the standard atmosphere at 10,000 ft elevation above MSL; (c) water at 60°F; and (d) crude oil with an API gravity of 21.47°API and a viscosity of 85.86 cP.
The answers are given, but I need to know how to solve them
a) 412 ft/s,
b) 480 ft/s,
c) 7.4 ft/s,
d) 6.2 ft/s.