A ball is kicked upward and then falls back down to its initial spot. Eddy wonders the maximum altitude will be if he knows the altitute as a function of time. .

What is known:

• The altitude function of the kicked ball is
  s = 30t - 5t².
• The units for displacement and velocity are m and m/s respectively

What is the maximum altitude the ball goes up?

• At the maximum altitude, the velocity of the ball is 0.
• Recall that velocity is simply the time derivate of displacement.