A projectile is thrown upward so that its distance above the ground after t seconds is given by the function h(t) = - 16t2 + 640t. After how many seconds does the projectile take to reach its maximum height? Show your work for full credit.

Question

eyust707 · Answer

To find a maximum we need to take the derivative, set that equation equal to zero, then solve for t.

anonymous · Answer

No calculus:
h(t)=-16(t^2-40t)
=-16(t-20)^2+6400
So maximum  (vertex) occurs at t=20.

With calculus:
h'(t)=-32t+640=0
Solve for t=20

eyust707 · Answer

@Ale01jandra  Do you understand that?