hello guys!

 

i have a column with a shape of a cylinder. the radius is 2cm and the heigh is 5cm. i have to calculate the cross-sectional area of the column. i wonder what is the formula and how is the calculation? it has been a long time since i last had my math lectures, so i really hope for some help!

 

thanks alot!

volume of a cylinder:

 

[i cant do maths symbols, i dont know how, im not into maths that much and have neva learnt how so...]

 

volume of a cylinder: pir^2h

 

or

 

pi X radius-squared X height.

 

so when r = 2 and h = 5

 

volume = pi X 2^2 X 5

volume = pi X 4 X 5

volume = pi X 20

volume = 62.83185 [to 5 D.P]

 

is that what you wanted?

You're not supposed to do it all for him.

but i couldnt do all the pi stuff and ^2 in proper mathematical symbols, i thought he'd get confused,

once he's got the formulae, anyone can use a calculator and replace r with 2 etc!

 

anyway, he's a new memeber, lets me nice to him at first!

 

how do you do all the maths symbols?

hi guys!

 

thanks for sharing, but i don't think we are right, since the answer must be in cm^2, which means it is not the volume of the column we are looking for. by the way what does it mean with cross-sectional area? is that the areal of the column?

 

yeah! and thanks for being nice to me due to my first visit here

thanks for sharing, but i don't think we are right, since the answer must be in cm^2, which means it is not the volume of the column we are looking for. by the way what does it mean with cross-sectional area? is that the areal of the column?

 

Nope. You have: [math]V = \pi r^2 h[/math], since r² is measured in cm² and h in cm, you have cm³, which is a volume.

how do you do all the maths symbols?

 

Use [math] tags.

hi Dave!

 

 

are you sure that cross-sectional area is the same like the areal of the column?

That's not cross sectional area. I apologise, I should've used V= instead of A= for that formula

 

[math]A = \pi r^2[/math]

[math]V = \pi r^2 h[/math].

so what is cross-sectional area?

[math]A=\pi r^2[/math]

by the way what does it mean with cross-sectional area? is that the areal of the column?

Assuming you're not supposed to take the cross-section "long-ways" (i.e. splitting it down the middle like string cheese), the cross-sectional area is the area of a slice through the object.

 

Since I can't think of a better way to describe it, the yellow circle in this picture is a cross-section. The area of the circle is the cross-sectional area.

thanks alot Dave and Woxor!

thanks alot Dave and Woxor!

 

No problem