Question

David kicks a soccer ball off the ground and in the air with an initial velocity of 35 feet per second. Using the formula H(t) = -16t2 + vt + s, what is the maximum height the soccer ball reaches?

17.9 feet

18.2 feet

18.7 feet

19.1 feet

Answer 1

@jim_thompson5910 @jdoe0001

Answer 2

what are v and s in that equation?

Answer 3

umm I think the v is 35, i might be wrong tho

Answer 4

v = 35 is correct

what is s

Answer 5

im not sure

Answer 6

s is the initial or starting height of the ball

Answer 7

which is 0?

Answer 8

v = 35
s = 0

yep

Answer 9

so the equation is

\[\Large H(t) = -16t^2 + 35t + 0\]

and that turns into

\[\Large H(t) = -16t^2 + 35t\]

Answer 10

ok now do I factor it?

Answer 11

How would you find the x coordinate of the vertex (for that equation)?

Answer 12

no you wouldn't factor

Answer 13

give me a second

Answer 14

if you're not sure, here's a page that shows an example

http://hotmath.com/hotmath_help/topics/vertex-of-a-parabola.html

Answer 15

I'm still a little confused

Answer 16

does the page help at all?

Answer 17

I tried finding the vertex on mathway and it said a solution could not be calculated

Answer 18

oh you used their special calculator?

Answer 19

yes

Answer 20

it could be a glitch, so why not try it by hand

Answer 21

what are 'a' and 'b' in the case of \[\Large H(t) = -16t^2 + 35t\]

Answer 22

okay .. i can try

Answer 23

(35/32),(1225/24)

Answer 24

I think you meant to say the vertex is (35/32, 1225/24)

Answer 25

yes lol

Answer 26

it's close, but not quite

Answer 27

is that correct?

Answer 28

no, you got the x coordinate correct

Answer 29

oh dang it

Answer 30

plug t = 35/32 into \[\Large H(t) = -16t^2 + 35t\] and evaluate to find the y coordinate

Answer 31

(0,0)???

Answer 32

wait.. (35,16)

Answer 33

I have no idea how you're getting that

Answer 34

neither do i >.<

Answer 35

\[\Large H(t) = -16t^2 + 35t\]

\[\Large H\left(\frac{35}{32}\right) = -16 \left(\frac{35}{32}\right) ^2 + 35\left(\frac{35}{32}\right)\]

\[\Large H\left(\frac{35}{32}\right) = ???\]

Answer 36

I'm not sure..

Answer 37

use a calculator if you need to (wolfram alpha is a good calculator to evaluate expressions like that)

Answer 38

am i just evaluating it ?

Answer 39

it said the result was 1..

Answer 40

yes

Answer 41

it's not 1

Answer 42

thats what wolfram said

Answer 43

this is really confusing

Answer 44

can you show me?

Answer 45

take a screenshot and post what you got

Answer 46

i can't screen shot on my computer

Answer 47

it won't let me put it as a fraction.. thats the problem

Answer 48

you hit the printscreen key

Answer 49

are you typing in 35/32 to represent \(\Large \frac{35}{32}\) ?

Answer 50

yes, it won't let me put it as a fraction :/

Answer 51

what are you typing in exactly into wolfram alpha? Paste it here

Answer 52

H(35/32)

Answer 53

that's all?

Answer 54

you were supposed to type in the right side, not the left

Answer 55

there was only one box to type it, can you send me the link to wolfram?

Answer 56

you type in

-16(35/32)^2 + 35(35/32)

Answer 57

it says: exact result 1225/24

Answer 58

i think i got the answer

Answer 59

19.1?

Answer 60

are you sure? are you sure it's over 24?

Answer 61

i mean 64

Answer 62

sorry

Answer 63

that's fine

Answer 64

so yeah, 1225/64 = 19.140625

Answer 65

yes.. now im wondering if i send another question if you could verify my answer? i just need a second opinion

Answer 66

ok go ahead

Answer 67

If 6c = 4T2 - 50, which of the following could T possibly be?

T = square root of negative 6 times C plus 50 over 4

T = square root of negative 6 times C minus 50 over 4

T = square root of 6 times C minus 50 over 4

T = square root of 6 times C plus 50 over 4

Answer 68

I chose the last one

Answer 69

does the last one say

\[\Large T = \sqrt{ \frac{6c+50}{4} } \]

??

Answer 70

yes

Answer 71

it's correct

Answer 72

okay ... Sarah wants to hang a painting in a gallery. The painting and frame must have an area of 75 square feet. The painting is 8 feet wide by 9 feet long. Which quadratic equation can be used to determine the thickness of the frame, x?
x2 + 17x - 3 = 0

x2 + 17x + 75 = 0

4x2 + 34x + 75 = 0

4x2 + 34x - 3 = 0


I chose the third one

Answer 73

that's incorrect

Answer 74

what equation do you start off with?

Answer 75

first i multiplied 9 times 8

Answer 76

wait.. i think its the first one

Answer 77

am i right?

Answer 78

hint: find the area of this rectangle

Answer 79

it might help to break it up like so