Question

Please Help!! No Idea how to work this out!! :( medal and fan if possible!!

Answer 1

If an object is dropped from a height of 195 feet, the function h(t) =−16t^2+195 gives the height of the object
after t seconds. When will the object hit the ground?
a. 3.49 s c. 13.96 s
b. 1.75 s d. 6.98 s

Answer 2

h(t)= 16t^2 + 195

Answer 3

when it hits the ground its height is 0

Answer 4

0=16t^2+195

Answer 5

solve for time

Answer 6

I am not sure how :/

Answer 7

do i have to divide or something?

Answer 8

@dan815 please? I literally have no idea how to solve for the time

Answer 9

yeah we want to isolate for t

Answer 10

both sides of the equations are equal we can the same thing to both sides and it will still be equal

Answer 11

we can do*

Answer 12

0-195=-16t^2+195 -195
-195=-16t^2
-195/-16 = -16/-16 * t^2
(-195/-16)=t^2

t=sqrt(195/16)

Answer 13

ok, I did that the only part i didnt make it to was

t=sqrt(195/16)

3.49?

Answer 14

here is a good place to check your answers
http://www.wolframalpha.com/input/?i=0%3D-16t^2%2B195

Answer 15

3.49 is right

Answer 16

thank you, i have one more, but using what you just taught me, i already solved it. would you mind checking it just realy quick?

Answer 17

nevermind, i just used the wolfram alpha xP

Answer 18

good :)