Ferris Wheel 9Abace
1. **Problem:** Model the altitude of Nikki's seat on the Ferris wheel over time using a sine function.
2. **Given Data:** Time (s): 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60
Altitude (m): 2, 2.8, 5, 8, 11, 13.2, 14, 13.2, 11, 8, 5, 2.8, 2
3. **Step 1: Identify key parameters of the sinusoidal function**
- The maximum altitude is 14 m.
- The minimum altitude is 2 m.
- The period is the time for one full cycle. From the data, the altitude returns to 2 m at 60 seconds, so the period $T = 60$ seconds.
4. **Step 2: Calculate amplitude and vertical shift**
- Amplitude $A = \frac{\text{max} - \text{min}}{2} = \frac{14 - 2}{2} = 6$
- Vertical shift (midline) $D = \frac{\text{max} + \text{min}}{2} = \frac{14 + 2}{2} = 8$
5. **Step 3: Write the general sine function form**
$$ h(t) = A \sin(B(t - C)) + D $$
where
- $A$ is amplitude,
- $B = \frac{2\pi}{T}$ is the angular frequency,
- $C$ is the phase shift,
- $D$ is the vertical shift.
6. **Step 4: Calculate $B$**
$$ B = \frac{2\pi}{60} = \frac{\pi}{30} $$
7. **Step 5: Determine phase shift $C$**
- At $t=0$, altitude is minimum (2 m), but sine function starts at zero.
- Sine function reaches minimum at $\frac{3\pi}{2}$ radians.
- So, set inside sine to $\frac{3\pi}{2}$ at $t=0$:
$$ B(0 - C) = -B C = \frac{3\pi}{2} \implies C = -\frac{3\pi}{2B} = -\frac{3\pi/2}{\pi/30} = -45 $$
- Negative phase shift means shift right by 45 seconds.
8. **Step 6: Write the final equation**
$$ h(t) = 6 \sin\left(\frac{\pi}{30}(t - 45)\right) + 8 $$
9. **Interpretation:** This equation models Nikki's seat altitude over time, oscillating between 2 m and 14 m with a period of 60 seconds.
**Final answer:**
$$ h(t) = 6 \sin\left(\frac{\pi}{30}(t - 45)\right) + 8 $$