## anonymous one year ago A water tank 3m in diameter and 6m high is made from a steel taving a thickness of 12mm. When tank is filled w/water determine the circumference stress. Det. the tank stressL at the buttom of the tank when it is filled w/water. if the circumference stress is limited to 5Mpa what is the max. height of the water?

1. Jack1

Volume of tank = ? @patbigFat

2. anonymous

not stated sir ..

3. Jack1

nono... can u work it out please?

4. Jack1

|dw:1439458968517:dw|

5. anonymous

V=Pi x r ^2 x h ?

6. Jack1

yup

7. anonymous

is it 169.6464m?

8. Jack1

no

9. Jack1

what are u using for r?

10. anonymous

11. Jack1

yeah... what number are u plugging into ur equation tho... for r?

12. anonymous

3 sir?

13. Jack1

no... 3 = diameter radius is half of diameter

14. Jack1

so give it another shot with r = 1.5 so V=??

15. anonymous

56.54 m3

16. Jack1

i got 42.41... how are u calculating this? 3.14159 x 1.5^2 x 6 =42.4115

17. anonymous

my mistake sorry ..

18. Jack1

all good dude now... surface area of inside of tank? = ??

19. anonymous

i tot when i sqr 1.5 = 3 so i did a manual calculating .... my bad....

20. anonymous

SA = 2 × pi × r2 + 2 × pi × r × h ?

21. anonymous

70.686 m^2 ?

22. anonymous

guyz help?

23. IrishBoy123

hoop stress $$\large \sigma_{\theta} = \frac{P \ D}{2t}$$ D = 3, t = 12mm get pressure from bernoulli $$P = \rho g h$$ h = 6 plug and play [if you know some calculus, the formula is deriveable; but i think it is also pretty standard for thin walled pressure vessels. been ages since i did this stuff.] you can get steel's material properties online, for the end bit you will need its tensile strength and the hoop stress is measured around the circumference , ie tangentially to the circle

24. IrishBoy123

actually you don't need to look at steel at all you are told "the circumference stress is limited to 5Mpa" so you are now solving h for a given $$\sigma_{\theta}$$

25. anonymous

Uhmm.m P=pgh by the way what's "pg" ?

26. IrishBoy123

$$\rho \equiv$$ density of fluid, here water g $$\equiv$$ gravity = $$9.8 m/s^2$$

27. Jack1

sorry guys, fell asleep last night

28. Jack1

howd u go with this?