College question

[joe brown]

I have been given a question at college and have been told there will be more during my course exams. It involves pi.

I am new to pi and have never ever learnt it or used it. The question is

Q. What is the capacity of the cylinder if the cylinder is 1 meter high 450mm diameter.

Then they give us the formula which is pi r2 x lenth x 1000

and then the answer which is 159 litres

So ok firstly what the dang is r2 and how do i get 159 from all that, Could somebody please show all the figures and explain bit by bit so i have a better understanding of how they came up with the answer.

I would gratefully appreciate it.

thank you joe

 

[arfurdaley]

I have been given a question at college and have been told there will be more during my course exams. It involves pi.

I am new to pi and have never ever learnt it or used it. The question is

Q. What is the capacity of the cylinder if the cylinder is 1 meter high 450mm diameter.

Then they give us the formula which is pi r2 x lenth x 1000

and then the answer which is 159 litres

So ok firstly what the dang is r2 and how do i get 159 from all that, Could somebody please show all the figures and explain bit by bit so i have a better understanding of how they came up with the answer.

I would gratefully appreciate it.

thank you joe

pi = 3.14

your diameter is 450mm (0.45m) so your radius (r) = 0.225m

r2 is your radius squared (r x r)

your length is the height of the cylinder (1m)

so

pi r2 x length x 1000

is

3.14 x (0.225 squared) x 1 x 1000

3.14 x (0.050625) x 1 x 1000

=158.96 round up to 159

Hopefully thats right.

 

[joe brown]

Thankyou very very much, I understand completely now, Everyone else was throwing figures at me but i have it now i think.

 

[stevetheplumber]

Thankyou very very much, I understand completely now, Everyone else was throwing figures at me but i have it now i think.

r2 is radius squared which as already stated means r times r
theres two formulas for circle
pi r squared eqals area of a circle
2 pi r which gives you the circumference
just remember the formula with the square will give you an answer in square ie area

 

[joe brown]

Thank you steve il bare that in mind

 

[Blackcatgas]

Good stuff!,and yet people still think that plumbing is suitable for non accedemic "thickies".