Comment on Activity 2

1. The initial value problem for `y` is

   `(dy)/(dt)=-ky`  with  `y text[(]0 text[)]=-g/k.`

2. The solution of the initial value problem in (a) is

   `y=-g/ke^(-kt).`

   This gives a formula for `v` as a function of `t`:

   `vtext[(]t text[)]=g/k(1-e^(-kt)).`
3. The formula shows that `vtext[(]t text[)]->g/k` as `t->oo`.

Note that we have already used this solution-by-substitution technique in Chapter 3 to solve the murder victim problem.