Homework Help: Drag force/difficult integral.

1. The problem statement, all variables and given/known data
If a ping pong ball is released from rest, how long does it take for the ping pong ball to reach 90% of its terminal velocity?

m=2.2g, density(air)=a.29kg/m^3, Cw=.5, diameter=.38mm


2. Relevant equations
Fd=1/2*C[tex]_{w}[/tex]+[tex]\rho[/tex]*A*v^2

newton's second law



3. The attempt at a solution

I set up newtons second law for the going down case. I wanted to get v in terms of t.
I can't solve the integral though.

Fd-mg=m*dv/dt

[tex]\int \frac{dt}{m}[/tex]=[tex]\int \frac{2*dv}{C_{w}*\rho*A*v^2-mg}[/tex]

Please help.

 

yeah, i was able to get it to that form and it worked. Thanks.