Question

If h(t) represents the height of an object above ground level at time t and h(t) is given by: h(t)=-16t^2+14t+1

find the height of the object when at the time when the speed is zero.
h(t)=

(this problem is related to the previous problem that i posted: http://openstudy.com/study#/updates/4f20823ce4b076dbc348cc35)

Answer 1

wouldnt you just plug in 14 for t to get -32(14)+14=-434 or am i way off

Answer 2

this is differential calculus.... differentiate the function.... let the derivative = 0. This is when speed is zero....

The solution will give you the time (t) when the speed is 0.

Once you have a value for t substitute it into the original equation to get the height when speed = 0.

looks like t will be 7/16... which then needs to be substituted...

Answer 3

actually there are 2 solutions to this the one above and when t = 0 the speed is 0 as well....

Answer 4

where do i substitute 7/16?

Answer 5

the function i was given in the beginning?

Answer 6

????

Answer 7

yes

Answer 8

ok

Answer 9

i got a mixed number

Answer 10

that would be correct since ou substituted a fraction

Answer 11

i dont think my website accepts mixed numbers so i converted but i got the wrong answer when i did that

Answer 12

11 15/16

Answer 13

so i tried 191/16 which is wrong and i tried 11.9 which is also wrong

Answer 14

the fraction is (7)/(16 or seven sixteenths

Answer 15

yes, i know. what's the final answer?

Answer 16

there are 2 answers....1 and a value between 4 and 4.1

Answer 17

ok the correct answer is 4 (according to my hw site) how did you get 4?

Answer 18

by correctly substituting.... and knowing some calculus... sorry but this has become painful good luck with your solution

Answer 19

you couldve just showed ur work in the beginning so i wouldnt have asked so many questions but whatever -_-

Answer 20

this is a basic calculus concept.... please try and learn it, good luck