Lesson plan · Grade 11 · 50 minutes
Ferris Wheel
I can model a Ferris wheel ride with a sinusoid, read amplitude, midline and period from it, and explain radians as arc length on the unit circle.
- Hook5 min
- Explore15 min
- Make sense12 min
- Apply13 min
- Exit check5 min
Before class
- Open Ride with the defaults: radius 15 m, hub 18 m, one turn in 40 s, boarding at the bottom.
- Note the equation for the defaults: h(t) = 18 + 15 sin(2πt / 40 − π/2).
Hook 5 min
- Press Play and let the graph grow for one full turn. "What shape is this graph? Have you seen it anywhere else?"
- "Anything that repeats can be modeled this way: tides, sound, daylight. Today, a Ferris wheel."
Explore 15 min
- Pairs press Pause and drag the car a quarter turn. The graph dot jumps to t = 10 s, h = 18 m. Then they drag the dot to t = 30 s.
- Pairs change one slider at a time and ride again, recording which part of the graph changed: radius, hub height or time for one turn.
- Pairs try Board at each position and both Turn directions, and use Keep this graph to compare up to 3 curves.
- "Why do Bottom-counterclockwise and Bottom-clockwise give the same graph, but Right side does not?"
Make sense 12 min
- On the board, connect each slider to the equation: hub height is the midline, radius is the amplitude, time for one turn is the period.
- Switch to Unit Circle. Press One radian: a radius-length rod bends onto the rim. Wrap the string around the lid to show the same thing.
- Press Unroll the arc. "The height is sin θ. Why does about 6.28 of these fit around?"
- Turn on Show cosine. The identity line always reads 1.000. "Why must sin² θ + cos² θ = 1?"
Apply 13 min
- Pairs open Match and work through the target graphs. Check accepts any wheel within 0.5 m, so equivalent wheels count.
- Pairs who finish open Real Wheels and compare the London Eye with Chicago 1893. "The London Eye moves at about 0.21 m/s. Why can you barely feel it move?"
Exit check 5 min
On a card: "A wheel has radius 20 m, a hub 25 m high, turns once in 60 s, and you board at the bottom. Write h(t) and give the highest and lowest heights." Then: "Why is 18 + 15 sin(2πt / 40 − π/2) the same as 18 − 15 cos(2πt / 40)?"
Support and stretch
- Support: change only one slider at a time and write the equation after each change.
- Support: use Step π/6 and Step π/4 to read exact values.
- Stretch: turn on Show sideways distance and explain the live check x² + (h − D)² = r².
- Stretch: "A radian is about 57.3 degrees. Where does that number come from?"
Short on time
- Ride with one slider at a time (10 min).
- One radian in Unit Circle (5 min), then the exit card (5 min).
How each button works is in the teacher notes. From Curio Class, free under CC BY 4.0: change it, print it, share it.