Question

A ball is thrown up into the air such that its height (h) from the starting point is given by h(t) = 50t − 5t2, where t is the time (in seconds) elapsed from the moment the ball is released. During which time interval will the height of the ball be 80 meters or higher above the starting point?

[3, 6]

[4, 10]

[2, 8]

[2, 6]

Answer 1

hey

Answer 2

just set h(t) = 80 and then solve for t

so

\[80 = 50t - 5t^2~~~~or ~~~5t^2 - 50t + 80 = 0\]

Answer 3

2,8

Answer 4

that's it