Question

A ball is thrown from a height of
140
feet with an initial downward velocity of
8/fts
. The ball's height
h
(in feet) after
t
seconds is given by the following.
=h−140−8t16t2
How long after the ball is thrown does it hit the ground?

Answer 1

for it to hit the ground the height must be zero

Answer 2

I don't understand your function

Answer 3

but pretend we have the height is h
h(t)=5t^2+t
and we want to know when h is 0
replace h(t) with 0
0=5t^2+t
and solve for t

Answer 4

t=0,-1/5 @freckles

Answer 5

that is correct for the example function I gave

Answer 6

can't be 0 doesn't make sense

Answer 7

but as I said I do not understand what your function is

Answer 8

its for a class i didnt write it a teacher did

Answer 9

write it out using the equation thing

Answer 10

she really wrote "=h−140−8t16t2
"
because this makes no sense

Answer 11

h=140-8t-16t^2

Answer 12

ohhhh

Answer 13

ok replace h with 0

Answer 14

since we are given the height is 0

Answer 15

and you are looking for the second 0 not the first 0

Answer 16

then solve for t using factoring or quadratic formula

Answer 17

A ball is thrown from a height of
140
feet with an initial downward velocity of
8/fts
. The ball's height
h
(in feet) after
t
seconds is given by the following.

Answer 18

I think your copying and pasting is not working :p

Answer 19

but anyways you already corrected your function for h
so we know it now
can you replace h with 0 and solve for t?

Answer 20

ok thnaks =)

Answer 21

t=2.72 or t=-3.22

Answer 22

those are approximately right
and you should be looking for the second zero
that zero being t=2.72 (since this occur later)