OG13, 第五题帮帮我啊，谢谢

hollyyao

5. Aclosed cylindrical tank contains 36-rc cubic feet of
water and is filled to half its capacity. When the tank is
placed upright on its circular base on level ground, the
height of the water in the tank is 2 feet. When the tank
is placed on its side on level ground, what is the
height, in feet, of the surface of the water above the
ground?
(A) 2
(B) 3
(0 4
(D) 6
(E) 9
Using the information about the volume of water
in the upright cylinder, solve for this radius to
determine the height of the water when the
cylinder is on its side.
V = nr2h
36n = nr2h
36= r2(4)
9 = r2
3 = r
volume =(k)(radius2)(height)
known volume of water is 367T
substitute 4 for h; divide both
sides by n
solve for r
radius = height of the water
in the cylinder on its side

V = nr2h
36n = nr2h
36= r2(4)
9 = r2
3 = r
height是2呀，怎么答案里带入的是4. 因为是OG，不会错的，我哪里理解有误，呀，请赐教，谢谢

zxc1118zxc

is filled to half its capacity & the height of the water in the tank is 2 feet。
so height of cylindrical is 4

hollyyao

Thanks a lot.

I agree with you.so height of cylindrical is 4,
but closed cylindrical tank contains 36pai cubic feet of
water and is filled to half its capacity.

so the volume of the cylindrical is 72pai.