- #1

- 78

- 0

during the time interval 0<t<4, what is the average rate of water flow??

I'm confused whether to use the formula

f(4)-f(0) / (4-0)

OR

[tex]\frac{1}{4}[/tex][tex]\int[/tex]f(t) evaluated from 0 to 4.

help!!

You are using an out of date browser. It may not display this or other websites correctly.

You should upgrade or use an alternative browser.

You should upgrade or use an alternative browser.

- Thread starter fiziksfun
- Start date

- #1

- 78

- 0

during the time interval 0<t<4, what is the average rate of water flow??

I'm confused whether to use the formula

f(4)-f(0) / (4-0)

OR

[tex]\frac{1}{4}[/tex][tex]\int[/tex]f(t) evaluated from 0 to 4.

help!!

- #2

tiny-tim

Science Advisor

Homework Helper

- 25,836

- 254

Hi fiziksfun !

Hint: Suppose f(t) is a constant, C. Then f(4) = f(0) = C.

So which formula is right?

Hint: Suppose f(t) is a constant, C. Then f(4) = f(0) = C.

So which formula is right?

- #3

- 78

- 0

i'm kind of slow, so i still don't understand :[

can you help me more??

can you help me more??

- #4

tiny-tim

Science Advisor

Homework Helper

- 25,836

- 254

If f(t) = C, a constant, then obviously the average of f(t) is C.

But f(4)-f(0) / (4-0) = (C - C)/4 = 0, which obviously is wrong.

And ∫f(t)/4 = ∫C/4 (evaluated from t = 0 to 4) = C, which equally obviously is right!

This works for *any* f(t), because f(t) is the rate of water, so ∫f(t) is the total water.

And so the average rate of water = total/time = ∫f(t)/4.

And so the average rate of water = total/time = ∫f(t)/4.

- #5

- 78

- 0

ah, i think i understand, thank you!!!

Share:

- Replies
- 5

- Views
- 14K