A ball is shot out of a cannon. The height of the ball, h in meters, as a function of the time, t in seconds, since it was shot is given by the equation h= -5t^2 +30t +1h=5t2+30t+1. What is the maximum height?

1 Answer
Feb 23, 2016

46m46m

Explanation:

The maximum and minimum values will be at points where the derivative of this function is zero, ie
EE h_(min//max)iff (dh)/dt=0

iff-10t+30=0

ifft=3s.

Since the second derivative (d^2h)/(dt^2)|_(t=3)=-10<0,
it implies that t=3 is a relative maximum of the function h(t).

therefore h_(max)=h(3)

=-5(3^2)+30(3)+1

=46m.