Question

The formula for projectile motion is: h(t) = -16t2 + vot + so, where h is the height (at a given time t), vo is the initial velocity and so is the starting height.

A water balloon is launched straight up from the top of an 49 foot building with the initial velocity of 80 feet per second. Find the time interval when the water balloon's height exceeds 113 feet.

Answer 1

re-writing last sentence

Answer 2

h(t) = 113 < -16t^2 + 80t + 49

-16t^2 + 80t - 64 > 0

lets divide both sides by 16 to make it easier to look at.

-t^2 + 5t - 4 > 0

we can find t with the quadratic formula or by factoring. i factored.

(4 - t)(t - 1) > 0

*this equation is only true when t is between 1 and 4. therefore that is your interval.

if you have questions lmk

Answer 3

thanks