Question

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The function graphed approximates the height of a nail, in meters, x seconds after a construction worker drops it from a skyscraper.

After about how many seconds is the nail 50 m above the ground?

A. 3.2 s

B. 3.5 s

C. 3.9 s

D. 4.1 s

Answer 1

@Vocaloid

Answer 2

@Vocaloid

Answer 3

"After about how many seconds is the nail 50 m above the ground?"

notice that the y-axis represents height, so you would locate 50 on the y-axis and find the corresponding x-axis value

Answer 4

the answer is A

Answer 5

am i correct ?

Answer 6

which answer choice is closest to this x-value?

Answer 7

D.

Answer 8

look carefully, the x-value is less than 4.

Answer 9

OH I SEE,

Answer 10

try one more time, there's an answer choice that's closer to 4 but still less than 4.

Answer 11

Mark out A, B and D

Answer 12

so it's C

Answer 13

good

Answer 14

Joe will build a rectangular pen for his dog. A wall will form one side of the pen. Joe has 40 ft of fencing to form the other three sides.

Joe plans to build the pen so that it has its maximum possible area.


What will be the dimensions of Joe’s dog pen?

Enter your answers in the boxes.


ft _______ by _____ ft

Answer 15

the answer is 20 ft by 10 ft

Answer 16

good

Answer 17

Carissa takes a square piece of cardboard and cuts 5 in. by 5 in. squares out of each corner. She folds the sides up to make a box without a top.

What equation can Carissa use to determine the volume of the box, where x is the side length of the original piece of cardboard?



Express the equation in standard form.

Enter your answer in the box.

V =

Answer 18

if the original length of the box is 5, and we cut out 2 pieces each with length x, what would be the equation for the new length?

Answer 19

5x^2 - 100x + 500

Answer 20

I got something a little different than that

Answer 21

let's take it one side at a time

if the old length is 5 and we take away two pieces of size x, what would be the equation for the new length?

Answer 22

i had it but i just forgot it

Answer 23

well, if the squares were, say, 1 inch each, we would just subtract 5 - 1 - 1 since there are two pieces being taken away

so if we start with 5, take away 2 pieces each of length x, what would the new length be?

Answer 24

3

Answer 25

almost but not quite

if we start with 5 and take away x, we would subtract 5 - x

if we take away another piece x, we subtract 5 - x - x or 5 - 2x

make sense so far?

Answer 26

yes just about

Answer 27

now, if we look at the width, it's the same thing, we start with width 5 and take away two x-pieces to get 5 - 2x again

so length = 5 - 2x
width = 5 - 2x

for the height, when we "fold up" the flaps, we get a box with height x

so

volume = (5-2x)(5-2x)x

how would we express this equation in standard form?

Answer 28

4x^3 - 20x^2 + 25x

Answer 29

^ good so that would be your final answer

Answer 30

are you sure this right answer ?

Answer 31

cause i thought it was 5x^2 - 100x + 500

Answer 32

it's this

4x^3 - 20x^2 + 25x

since the width, length, and height all have x in them, the final answer must have x^3 in it which means 5x^2 - 100x + 500 can't be right

Answer 33

The function y=−16x^2 + v0x models Lindy's height in feet above a trampoline x seconds after she jumps straight up. In the equation of the function, v0 is her initial velocity in feet per second. Lindy lands back on the trampoline 1 second after she jumps.



What is the value of ​ v0 ​?

Enter your answer in the box.

v0 = ______ ft/s

Answer 34

16

Answer 35

well people on the internet are saying 5x^2 - 100x + 500 was right (for the Carissa box problem), I don't agree with that but if that's what the system is marking as correct then I guess go with that

Answer 36

yeah I got 16 for the Lindy problem too

Answer 37

A farmer has 300 ft of fencing with which to enclose a rectangular pen next to a barn. The barn itself will be used as one of the sides of the enclosed area.



What is the maximum area that can be enclosed by the fencing?

Enter your answer in the box.


________ ft²

Answer 38

I believe it's 11,250

Answer 39

yeah that's what I got too

Answer 40

yes that was correct 5x^2 - 100x + 500

Answer 41

and the other

Answer 42

one question, whenever i have a question or trying to reach you, how come you don't reply

Answer 43

even if you're there

Answer 44

I can't help people 24/7 sometimes I have to work on my own hw too

Answer 45

i understand that, but when i text you you don't reply back

Answer 46

if I don't reply please assume that I am occupied

Answer 47

ok that makes sense

Answer 48

but just next time could you remind me ?

Answer 49

and do you even get my messages ?

Answer 50

I do, I usually try to get back to people in the evenings

Answer 51

also do you know anybody who's good 100% at history ?