Difficult# Drag Force and Terminal Velocity: Drag Coefficient of a Sphere

CLMECH-XEE13H

A sphere with a mass of $160\space g$ and radius of $2.4\space cm$ is falling at its terminal velocity of $72\space m/s$. A force of air resistance of $\left |F_{air}\right | = \frac{1}{2}c\rho Av^2$ acts on the sphere, where $c$ is the drag coefficient, $\rho = 1.2\space kg/m^3$ is the density of the air, $A$ is the cross-sectional area of the sphere and $v$ is the speed of the sphere.

What is the drag coefficient for the sphere?