If a metal pipe 10cm long has an external diameter of 12c...
If a metal pipe 10cm long has an external diameter of 12cm and a thickness of 1cm find the volume of the metal used in making the pipe
120πcm3
110πcm3
60πcm3
50πcm3
Correct answer is B
The volume of the pipe is equal to the area of the cross section and length.
let outer and inner radii be R and r respectively.
Area of the cross section = (R2 - r2)
where R = 6 and r = 6 - 1
= 5cm
Area of the cross section = (62 - 52)π = (36 - 25)πcm sq
vol. of the pipe = π (R2 - r2)L where length (L) = 10
volume = 11π x 10
= 110πcm3
How many three-digit numbers can be formed from 32564 without repeating any of the digits? ...
The value of (0.03)3 - (0.02)3 is ...
The ages of students in a small primary school were recorded in the table below. Age 5...
The diagonals of a rhombus are 6cm and 8cm. Find the area of the rhombus. ...
Calculate the distance between points L(-1, -6) and M(-3, -5)...