Cone Radius
1. **State the problem:**
We are given the volume formula of a cone:
$$V = \frac{1}{3} \pi r^2 h$$
(a) Make $r$ the subject of the formula.
(b) Find the base radius $r$ of a cone with height $h = 17$ cm and volume $V = 14,732$ cm³, using $\pi r^2 = \frac{22}{7}$.
2. **Rearrange the formula to make $r$ the subject:**
Starting with:
$$V = \frac{1}{3} \pi r^2 h$$
Multiply both sides by 3:
$$3V = \pi r^2 h$$
Divide both sides by $\pi h$:
$$\frac{3V}{\pi h} = r^2$$
Take the square root of both sides:
$$r = \sqrt{\frac{3V}{\pi h}}$$
3. **Calculate $r$ using given values:**
Substitute $V=14,732$ cm³, $h=17$ cm, and $\pi r^2 = \frac{22}{7}$ (note: this suggests using $\pi = \frac{22}{7}$):
$$r = \sqrt{\frac{3 \times 14,732}{\frac{22}{7} \times 17}}$$
Calculate denominator:
$$\frac{22}{7} \times 17 = \frac{22 \times 17}{7} = \frac{374}{7}$$
Calculate numerator:
$$3 \times 14,732 = 44,196$$
So:
$$r = \sqrt{\frac{44,196}{\frac{374}{7}}} = \sqrt{44,196 \times \frac{7}{374}}$$
Calculate inside the root:
$$44,196 \times \frac{7}{374} = \frac{44,196 \times 7}{374} = \frac{309,372}{374} \approx 827.25$$
Take square root:
$$r \approx \sqrt{827.25} \approx 28.77$$
**Final answer:**
(a) $$r = \sqrt{\frac{3V}{\pi h}}$$
(b) The base radius $r$ is approximately $28.77$ cm.