A steel ball weighing 128 pounds is suspended from a spring. This stretches the spring $\frac{128}{65}$ feet.

The ball is started in motion from the equilibrium position with a downward velocity of $6$ feet per second.
The air resistance (in pounds) of the moving ball numerically equals 4 times its velocity (in feet per second) .

Suppose that after t seconds the ball is y feet below its rest position. Find y in terms of t. (Note that this means that the positive direction for y is down.)

$y=$

Take as the gravitational acceleration 32 feet per second per second.

Hint: