Problema Solution
A ball is thrown from an initial height of 7ft. with an initial velocity of 29ft/sec. the ball's height (h) in feet after t seconds is given by the following formula: h=7+29t-16t^2
Find all values of t for which the ball height is 19 feet. Round answers to nearest hundreth.
I am not sure how to get this into the quadratic equation. Would it be: 19=7+29t-16t^2 or 16t^2-29t+12 or 8t^2-14.5t+6 and then solve using the quadratic equation?
Thanks
Answer provided by our tutors
h(t)=7+29t-16t^2
t = ? for h(t) = 19 ft
7+29t-16t^2 = 19
-16t^2 + 29t - 12 = 0 multiply both sides by (-1)
16t^2-29t+12 = 0
by solving we find
t1 = 1.17 sec
t2 = 0.64 sec
click here to see the step by step solution of the quadratic equation
for t = 0.64 sec and t = 1.17 sec the height of the ball is 19 ft.