# Thread: Help with litres per minute calculations

1. ## Help with litres per minute calculations

Hiya, I am doing a homework about a subject we haven't really covered in class! It's very annoying.

I was just wondering if anyone would be able to help me with it. It's not so much the problem itslef, just the actual method. I just need to know if there is a litres/minute etc triangle? Like there is a distance, speed, time triangle, if that makes sense XD

If it's litres/minute I assumed that volume would go on the top spot and time udnerneath? If so, what would be in the last bottom one? Or am I completely wrong? :P

Hope you can help and hope it isn't too much trouble

Thanks,
Laura (Turple).

2. Originally Posted by Turple
Hiya, I am doing a homework about a subject we haven't really covered in class! It's very annoying.

I was just wondering if anyone would be able to help me with it. It's not so much the problem itslef, just the actual method. I just need to know if there is a litres/minute etc triangle? Like there is a distance, speed, time triangle, if that makes sense XD

Link to DST triangle:dst.jpg - Image - Photobucket - Video and Image Hosting

If it's litres/minute I assumed that volume would go on the top spot and time udnerneath? If so, what would be in the last bottom one? Or am I completely wrong? :P

Hope you can help and hope it isn't too much trouble

Thanks,
Laura (Turple).
The little boys and girls in primary school use triangles

Try figuring things out without the aid of these triangles.

Give us the problem if you're starting to struggling with it?

3. ## :o

Triangles are handy!!

Anyway, the problems:

1. A petrol pump fills a car with 32 litres of petrol in 2 minutes 8 seconds. Give this as a rate in

a) litres per second b) litres per minute c) litres per hour

2. Calculate the average flow of the water falling into the bath when 100 litres flow into the bath in 8 minutes.

Thanks

4. Originally Posted by Turple
Triangles are handy!!

Anyway, the problems:

1. A petrol pump fills a car with 32 litres of petrol in 2 minutes 8 seconds. Give this as a rate in

a) litres per second b) litres per minute c) litres per hour

2. Calculate the average flow of the water falling into the bath when 100 litres flow into the bath in 8 minutes.

Thanks
Ratio, Fraction, Dimensional Analysis

$\displaystyle \frac{32\;l}{2\;min\;8\;sec}\;=\;\frac{32\;l}{128\ ;sec}$

$\displaystyle \frac{32\;l}{128\;sec}*\frac{60\;sec}{1\;min}$

$\displaystyle \frac{32\;l}{128\;sec}*\frac{60\;sec}{1\;min}*\fra c{60\;min}{1\;hr}$

Do NOT let these scare you. Just WRITE THEM DOWN and let the notation help you. The notation is a much greater friend than the little triangle trick.

$\displaystyle \frac{100\;l}{8\;min}$ What's to calculate? Just write it down.

5. Originally Posted by Turple
Triangles are handy!!

Anyway, the problems:

1. A petrol pump fills a car with 32 litres of petrol in 2 minutes 8 seconds. Give this as a rate in

a) litres per second b) litres per minute c) litres per hour

2. Calculate the average flow of the water falling into the bath when 100 litres flow into the bath in 8 minutes.

Thanks
1.a) 2 mins 8 secs = 120 secs + 8 secs = 128 secs

Litres per second means litres OVER time(secs)

$\displaystyle \frac{32}{128} = 0,25 \ litres \ per \ sec$

1.b) Just multiply the answer in 1.a) by 60

1.c) Multiply the answer in 1.b) by 60

2.) Average flow, (let's take it as flow per minute): $\displaystyle \frac{100}{8} = 12,5 \ litres \ per \ min$

6. ## Thanks

Thankyou for you help