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? How do I set up the equation,i dont want answer...

Answer 1

i think this will be like a projectile motion but you need the initial direction of the velocity.

Answer 2

thats all the info i have...

Answer 3

assumung the ball is hit in vertical direction use the equations for constant acceleration

displacement = 0, acceleration = -32 ft /s/s, u = 25 ft/s, t = ?
equn is

0 = 25t - 1/2 * 32 * t^2

Answer 4

im using the equation h(t)=-16t^2+vt+s

Answer 5

yes - thas ok

Answer 6

so what do i plug in where for my equation. I tried -16t^2+25t then factored (-4t+5) (4t+5) . That right?

Answer 7

i know the answer is .8 but cant get that the way ive set it up

Answer 8

so im doing sumptin wrong

Answer 9

0 = 25t - 1/2 * 32 * t^2
25t - 16t^2 = o
t(25-16t) = 0
t = 25/16 secs

Answer 10

or 1.56 secs

Answer 11

is used the equation s = ut + (1/2) a t^2

Answer 12

0.8 is not correct answer

there are 4 constant acceleration equations worth remembering

v = u + at
s = ut + 0.5at^2
v^2 = u^2 + 2as
and
s = (u+v)t / 2

whre u = initial velocity
v = final velocity
s = displacement
t = time
a = acceleration

Answer 13

thank you so much. I undertand it now...