The water supply uses huge concrete pipes to drain stormwater. a Find the external radius of a pipe.

b Find the Internal radius of a pipe.

c Find the volume of concrete necessary to make one pipe.

a. External radius is 0.5 m.

b. Internal radius is 0.45 m.

c. Volume of concrete necessary to make one pipe is 0.37 .

Step-by-step explanation:

a. It can be observed that the diameter of the pipe is 1 m.

External radius =

          =

          = 0.5

External radius = 0.5 m

b. Internal radius of the pipe can be determined by;

Internal radius =

But,

Internal diameter = 1 m - (2 x 0.05 m)

                      = 1 m - 0.10 m

                      = 0.9 m

Internal diameter = 0.9 m

So that,

Internal radius =

                        = 0.45

Internal radius = 0.45 m

c. Volume of concrete required = h - h

where is the external radius, and is the internal radius.

Volume of concrete required = [ x x 2.5] - [ x x 2.5]

                                                = 1.9643 - 1.5911

                                                = 0.3732

The volume of concrete necessary to make one pipe is 0.37 .

13

step-by-step explanation:

169-1=168

168-3=165

165-5=160

160-7=153

153-9=144

144-11=133

133-13=120

120-15=105

105-17=88

88-19=69

69-21=48

48-23=25

25-25=0

since it took 13times to completely subtract it hence its square root is 13