An archer shoots an arrow into the air such that its height at any time, t, given by the function `h(t)=-16t^(2)+kt+3`. If the maximum height of the arrow occurs at 4 seconds after it is launched, what is the value of k?

A model rocket is launched vertically into the air such that its height at any time, t, is given by the function h(t)=-16t^(2)+80t+10 . What is the maximum height attained by the model rocket?

A ball is thrown in the air. Its height at any time t is given by h = 3+14t-5t^2 . Find the maximum height it can reach.

A stone is thrown vertically up and the height s reached in time t is given by s=80t-16t^2 . The stone reaches the maximum height in time t =

A stone is thrown up vertically and the height x ft it reached in t seconds is x=(80)t -(16)t^(2) . It reached the maximum height in time t=

Joe throws a ball upwards from a height of 12 feet from ground level. The height of the ball above the ground after time t second from when the ball was thrown is given by the expression h(t)= -t^(2)+at+b . The ball comes back to the ground after 8 second. What is the value of (a+b)?

A particle is fired straight up from the ground to each a height of x feet in t seconds, where x (t) =128t-16t^(2) . (1) Compute the maximum height of the particle reached. (2) What is the velocity when the particle hits the ground ?

Joe throws a ball upwards from a certain height above the ground level. The height of the ball above the ground after time t seconds from when the ball was thrown is given by the expression h(t)= -(t-a)^(2)+b . The ball reaches a maximum height of 25 feet after 4 seconds. After how much time [in seconds] will the ball reach the ground level?