1. **Problem statement:**
We have a frustum formed by removing a small cone from a larger similar cone. The small cone has radius $6$ m and height $10$ m. The frustum height is $50$ m. We need to find:
a) The radius of the original large cone.
b) The volume of the frustum to the nearest integer.
2. **Understanding similarity:**
Since the small cone and the original large cone are similar, their corresponding dimensions are proportional.
3. **Calculate the radius of the original large cone:**
Let the radius of the original large cone be $R$ and its height be $H$.
We know the small cone height $h = 10$ m and radius $r = 6$ m.
The frustum height is $50$ m, so the total height of the large cone is:
$$H = h + 50 = 10 + 50 = 60$$
Using similarity of triangles:
$$\frac{r}{h} = \frac{R}{H} \implies \frac{6}{10} = \frac{R}{60}$$
Cross-multiplied:
$$6 \times 60 = 10 \times R$$
$$360 = 10R$$
Divide both sides by 10:
$$\cancel{10}R = \frac{360}{\cancel{10}}$$
$$R = 36$$
So, the radius of the original large cone is $36$ m.
4. **Calculate the volume of the frustum:**
The volume of a cone is:
$$V = \frac{1}{3} \pi r^2 h$$
Volume of the large cone:
$$V_{large} = \frac{1}{3} \pi R^2 H = \frac{1}{3} \pi (36)^2 (60)$$
Calculate:
$$V_{large} = \frac{1}{3} \pi \times 1296 \times 60 = \frac{1}{3} \pi \times 77760 = 25920 \pi$$
Volume of the small cone:
$$V_{small} = \frac{1}{3} \pi r^2 h = \frac{1}{3} \pi (6)^2 (10) = \frac{1}{3} \pi \times 36 \times 10 = 120 \pi$$
Volume of the frustum:
$$V_{frustum} = V_{large} - V_{small} = 25920 \pi - 120 \pi = 25800 \pi$$
Approximate using $\pi \approx 3.1416$:
$$V_{frustum} \approx 25800 \times 3.1416 = 81036.48$$
Rounded to the nearest integer:
$$\boxed{81036}$$
**Final answers:**
- Radius of the original large cone: $36$ m
- Volume of the frustum: $81036$ cubic meters
Frustum Cone A485A0
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