Limits and variables?

[edahcs]

I am having a lot of trouble solving this problem. My teacher hasn't been much help to me either sadly...I just do not understand how to calculate the limit when all you have is variables. I am also confused with the limiting velocity. Here is the problem:

 

[DrLee]

At t grows very large, the value of the exponential approaches zero. So lim v(t) as t approaches infinity is simply v*. v* is the terminal velocity.

Part b of the problem is easily solved by setting the exponential equal to .01 and tolving for t as a function of v*.