Question

4. Using the formula for the volume of a cylinder, , find h when V = 141.3 and r = 3. Use pi = 3.14.

Answer 1

$\text{The formula of a volume of a cylinder}\\\\V=\pi r^2h\\\\\text{We have}\ V=141.3\ \text{and}\ r=3.\ \text{Substitute}\\\\\pi(3^2)h=141.3\\\\9\pi h=141.3\qquad|\text{divide both sides by}\ 9\pi\\\\h=\dfrac{141.3}{9\pi}\qquad|\text{use}\ \pi\approx3.14\\\\h=\dfrac{141.3}{9\cdot3.14}\\\\h=\dfrac{141.3}{28.26}\\\\\boxed{h=5}$