An Artisan has 63 kg of metal of density 7,000kg/m3. He intends to use make a rectangular pipe with external dimensions 12 cm by 15 cm and internal dimensions 10 cm by 12 cm. Calculate the length of the pipe in meters.

Answer 1

the cross-section of the pipe is a rectangular ring with area
A = (12*15)-(10*12) = 60 cm^2
so, if the pipe has length x meters, its volume is (60/100)^2*x = 36x/100 m^3
since mass = density * volume, we have

7000*36x/100 = 63
x = 63/2520 = 1/40 m

Answer 2

its allitle bit challemging though

Answer 3

its allitle bit challenging though

Answer 4

Volume=63kg ÷ 7000kg/m^3
=0.009m^3
Cross section Area = (12×15)-(10×12)=60cm
60cm^2=0.006m^2
0.009m^3÷0.006m^2= 1.5m
Answer =1.5metres

Answer 5

On my side I speculate, the question was supposed to have asked the volume of the material required to make the pipe,
That is you have to find difference in cross-sections multiplied by the height.

Answer 6

Why do we subtract 180 and 120 to find the product of width and height ?