Question

"The volume of a cylinder V is equal to the product of π and square of radius r and the height h". Express this statement as a formula. Make r the subject formula. Find r, when V = 44cm³, π = `(22)/(7)`, h = 14cm.

Answer 1

Volume of cylinder = V
Product of π and Square of radius r and the height h = πr²h

i.e. V = πr²h

V = πr²h

⇒ `"V"/("h"pi)` = r² 

⇒ r = `sqrt("V"/(pi"h")`

When V = 44cm³ , π = `(22)/(7)`, h = 14cm

⇒ r = `sqrt(44/(22/7 xx 14)`

= `sqrt(1)`
= 1cm.