Question

The curved surface area of a cylindrical pillar is 132m2 and its volume is 99m3. Find the diameter and the height of the pillar.


Pls tell

Answer 1

Answer:

curved surface area=132m²

2πrh=132

2×22/7 rh=132

rh=132×7/2×22

rh=21

r=21/h....,.......1

volume=99m³

πr²h=99

from eq. 1

π(21/h)²h=99

22/7×21×21/h=99

22×3×21=99×h

h=22×3×21/99

h=14m answer

Answer 2

ANSWER:- Let the radius of the pillar be r metres and its height be h metres.

CSA = 132m² ---------- 2πrh = 132

volume = 99 ----------- πr²h = 99

Dividing (2) by (1), we get

πr²h/2πrh = 99/132 ----- r = 2×99/132 = 3/2 = 1.5m

Diameter of the pillar = 2r = 2×1.5 = 3

Now, substituting r = 1.5 m in (1), we get

2×22/7×1.5×h = 132

h = 132×7/2×22×1.5 = 14

Hence, height of the pillar = 14 m