Question

A bucket catches water dripping from a leak in the ceiling. About 0.8 L drips into the bucket per hour. Lara graphs the number of liters in the bucket versus time. She plots the number of liters in the bucket along the vertical axis, and she plots time in hours along the horizontal axis.



What is the y-intercept of the line?

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Answer 1

@AriPotta

Answer 2

@chosenmatt

Answer 3

can you help me @jtvatsim

Answer 4

I think so... just give me a minute to sort out the problem. :)

Answer 5

kk

Answer 6

Alright, so we are thinking of how much water has dripped into the bucket over time. We should begin with a graph like this...

Answer 7

okay

Answer 8

Now, let's think about what the graph will look like as time goes on. Do you think we'll get more or less water in the bucket as time goes on?

Answer 9

i dont now

Answer 10

im sorry

Answer 11

OK. No problem. Take a look at the question... it says the bucket is catching water from the ceiling...

Answer 12

okay

Answer 13

So, if you left the bucket there for an hour (for example) would you expect there to be more or less water in the bucket?

Answer 14

yes

Answer 15

OK, we would expect to have more water in the bucket. Just like if you filled up the bucket in the sink... the longer you wait, the more water you get. :)

Answer 16

This means that our graph will look something like this...

Answer 17

see how the amount of water gets bigger the longer we wait?

Answer 18

yes

Answer 19

Now, the question is "what is the y-intercept"

Answer 20

Remember that the y-intercept is just the amount of water you have in the bucket when you start.

Answer 21

So, right when you put the bucket down, we want to know how much water is inside

Answer 22

so the y-intercept is 0.8

Answer 23

i mean 0.8

Answer 24

Close. :) They are being a little tricky though... 0.8 is how much water you gain after an hour.

Answer 25

Notice they said, "About 0.8 L drips into the bucket per hour"

Answer 26

So, after an hour, we will have 0.8. But, we want to know how much water before we start.

Answer 27

Actually, to answer that we just have to use common sense (no math).

Answer 28

When you put the bucket down there is no water inside of it, does that make sense?

Answer 29

yes

Answer 30

So, when we start we have 0 in the bucket.

Answer 31

That means that the y-intercept (the amount of water when we start) is 0.

Answer 32

m = 0.8 L/hr
the equation is y = 0.8t

The y-intercept is (0,0)

Answer 33

Yes, that is correct.

Answer 34

so its 0

Answer 35

that is right

Answer 36

Does that make sense? Any questions? :)

Answer 37

thx so much and thx for your explication

Answer 38

No worries, word problems are tricky. But just think about the real-life situation. :) Good luck!