Jules kicks a soccer ball off the ground and into the air with an initial velocity of 25 feet per second. Assume the starting height of the ball is 0 feet. Approximately, how long does it take until the soccer ball hits the ground again?

0.6 sec

0.8 sec

1.6 secs

2.8 secs

Question

Jules kicks a soccer ball off the ground and into the air with an initial velocity of 25 feet per second. Assume the starting height of the ball is 0 feet. Approximately, how long does it take until the soccer ball hits the ground again?

0.6 sec

0.8 sec

1.6 secs

2.8 secs

dumbcow · Answer

i believe height function to be used here is:
h(t) = -16t^2 +vt
where v is initial velocity
v = 25
h =0 when it hits the ground

0 = -16t^2 +25t
16t^2 = 25t
16t = 25
t = 25/16