1. **State the problem:**
Megan rode a penny-farthing where the big wheel has radius 36 units and made 9 complete rotations. The small wheel has radius 12 units. We need to find:
a) The distance Megan rode.
b) The number of complete rotations the small wheel made.
2. **Formula for distance traveled by a wheel:**
The distance traveled by a wheel after one complete rotation is the circumference of the wheel, given by:
$$\text{Circumference} = 2\pi r$$
where $r$ is the radius of the wheel.
3. **Calculate distance Megan rode:**
- Radius of big wheel $r_b = 36$
- Number of rotations $n_b = 9$
Distance traveled by big wheel:
$$\text{Distance} = n_b \times 2\pi r_b = 9 \times 2\pi \times 36$$
Calculate:
$$= 9 \times 72\pi = 648\pi$$
Approximate using $\pi \approx 3.1416$:
$$648 \times 3.1416 = 2036.7$$
So, Megan rode approximately **2036.7 units**.
4. **Calculate rotations of the small wheel:**
- Radius of small wheel $r_s = 12$
- Distance traveled is the same for both wheels.
Number of rotations of small wheel $n_s$:
$$n_s = \frac{\text{Distance}}{\text{Circumference of small wheel}} = \frac{648\pi}{2\pi \times 12}$$
Simplify:
$$= \frac{\cancel{648}\pi}{2\pi \times \cancel{12}} = \frac{648}{24} = 27$$
So, the small wheel made **27 complete rotations**.
**Final answers:**
- a) Distance Megan rode: **2036.7 units** (to 1 decimal place)
- b) Small wheel rotations: **27**
Penny Farthing Rotations 9463E4
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