Learn About Circles & Find Radius

  • Thread starter Thread starter thomas576
  • Start date Start date
  • Tags Tags
    Circles
AI Thread Summary
The discussion focuses on understanding circles, specifically the relationship between circumference, diameter, and radius, using the value of pi (approximately 3.14). A user explains their process of calculating the radius from a given circumference of 6π, leading to a diameter of 6 and a radius of 3. Participants clarify the correct symbol for pi and suggest using LaTeX code to display it properly. The conversation also includes light-hearted comments about pie, but the main emphasis remains on the mathematical concepts. Overall, the thread effectively combines learning about circles with community engagement.
thomas576
Messages
20
Reaction score
1
circles... and pie

ok so i found this site and I am learning about circles now :) http://www.mathgoodies.com/lessons/vol2/circumference.html

it says pie is 3.14 which is what you get when you divide the outer measurement of the circle by the diameter (pie being 3.14 as per his homework)

c/d=3.14 the question reads
in this problem i have used & to mean pie because i don't know how to make that symbol
circumference of a circle is 6&
find the radius...

so

6&/d=&

6(3.14)/d=3.14
18.84/d=3.14
18.84=3.14d
18.84/3.14=d
6=d
diameter is 2x radius so raidus is 3

sound right?
thanks again guys and gals!
 
Physics news on Phys.org
Its right.

You couldve saved some time by dividing both sides by pi in the first step
 
Just for reference, it is written pi. You can get the pi symbol by using LaTeX code. You write tex or itex in brackets and close them with /tex or /itex in brackets. Write \pi inbetween the code to get the symbol to show up.

Like this: \pi, click the symbol to see the code to write it.
 
thomas576 said:
in this problem i have used & to mean pie because i don't know how to make that symbol circumference of a circle is 6&

I like pie :-p However, I believe you are referring to the mathematical constant which whozum correctly spelled pi ..

If you want to make the symbol \pi click on the one I made and a popup window will show the syntax you can use, to create it)

(while I was writing this, i see Candyman has a similar suggestion, I wonder if he/she also likes pie :-p )
 
mmmmm...pie...
 
FredGarvin said:
mmmmm...pie...
You are too late, Fred. I sneaked up on it all unnoticed yesterday.
You're welcome to the left-overs, however :smile:
 
Last edited:
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top