Question

Help me please.

Answer 1

?

Answer 2

with what?

Answer 3

An Li projected a ball into the air at 32 feet per second from a platform 48 feet off the ground. The path of the ball is represented by the equation s(t) = -16tsquared + 32t + 48, where s is the height of the ball and t is the time, in seconds, after the ball was projected. How many seconds will it take the ball to reach the ground?

Answer 4

Answer choices:
a - 1
b - 2
c - 3
d- 4
Please explain. ;3

Answer 5

set s(t) = 0

Answer 6

when ball is on the ground, height is 0.

Answer 7

try plugging in the answer in the variable and see if it matches up

Answer 8

^ or do that.

Answer 9

hahah it works ya know!

Answer 10

Oh s(t) = 0?

Answer 11

which one of those answers makes 0

Answer 12

For the t_squared do we actually have to square it

Answer 13

Im still confused...Im bad at math :/

Answer 14

same here but i try even though what your doing is beyond my level

Answer 15

After you set it to zero, what method are you pose to use?

Answer 16

like i said try plugging in the answer into the T and see what you get if which one will equal the zero=s(t)

Answer 17

Is 0 pose to = 0 when you get the right answer o-o

Answer 18

ok i got it the answer should be t=3

Answer 19

well, you're finding t, so s(t) = 0, find t.

Answer 20

Okie I get it just keep plugging Q~Q So much work. Ty.

Answer 21

no, don't just keep plugging in, it won't work in the future if it's not multiple choice.

Answer 22

Oh its for getting ready for cst

Answer 23

it's a waste of time on a test also.

Answer 24

only plugg in to find answer but eventualy youll need to work it out to get the answer you got

Answer 25

I dont gte how to find it by setting it to 0 tho

Answer 26

set it to 0, then isolate for t. what do you not get.

Answer 27

take your equation for the path of the ball, notice how everything in the equation is a mulitple of 16? we can take out that sixteen and get rid of it because we only want to know when your equation =0

your new equation:

(-x^2 +2x +3)=0
we can factor this into

(-x+3)(x+1)=0
the equation will be zero when either of these = 0
from this we can have 2 answers:
one at x=-1
one at x=3
since time can't go backwards, the only answer we have left is at x=3

Answer 28

isnt there more than one t tho?
so how do you isolate. o-o

Answer 29

yes, there is more than one t. if you look at my solution you will see that i have 2 "x"s that work, but one of them is negative, so we can't use it as a solution, because the ball can't go back in time

Answer 30

OMG. I cant believe I fogot that. Lol. My teacher taught me that three days ago...

Answer 31

Ty.

Answer 32

Np. Better than studying Calculus 4 like i should be

Answer 33

Im not in that grade tho. Lol.

Answer 34

forget grade, try university year

Answer 35

Lol.