Problema Solution
A ball is thrown vertically upward from the ground. It's distance in feet from the ground in t seconds is s= -16t^2+128t. After how many seconds will the ball be 240 feet from the ground?
Answer provided by our tutors
s= -16t^2+128t
if s = 240 feet what is the value of t?
-16t^2+128t = 240
-16t^2+128t - 240 = 0
by solving the quadratic equation we find
t1 = 3 seconds
t2 = 5 seconds
after 3 seconds the ball will be 240 feet from the ground.
after 5 seconds the ball will be 240 feet from the ground.