Rotational Speed of a Bicycle Wheel

 To find the RPM (revolutions per minute) of a bicycle wheel, we can follow this step-by-step method:

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Given:

• Tire diameter = 26 inches

• Speed = 10 miles per hour (mph)

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Step 1: Convert speed to inches per minute

1 mile = 63,360 inches
So,
10 miles/hour = 10 × 63,360 = 633,600 inches/hour

Convert to inches per minute:

$$\frac{633,600\ \text{inches/hour}}{60\ \text{minutes/hour}} = 10,560\ \text{inches/minute}$$

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Step 2: Find wheel circumference

Circumference of a circle = π × diameter

$$C = \pi \times 26 \approx 81.68\ \text{inches}$$

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Step 3: Calculate RPM

$$\text{RPM} = \frac{\text{linear speed in inches/min}}{\text{wheel circumference}} = \frac{10,560}{81.68} \approx 129.3$$

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✅ Answer: The wheels rotate at approximately 129.3 RPM at 10 mph.

You said:

Convert 130 RPM to rotations per second

ChatGPT said:

To convert 130 RPM (rotations per minute) to rotations per second (RPS):

$$\text{RPS} = \frac{\text{RPM}}{60} = \frac{130}{60} \approx 2.17$$

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✅ Answer: 130 RPM is approximately 2.17 rotations per second.

You said:

convert 2.17 rotations per second to milliseconds per degree

ChatGPT said:

To convert 2.17 rotations per second to milliseconds per degree, follow these steps:

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Step 1: Find time per rotation in milliseconds

$$\text{Time per rotation} = \frac{1}{2.17\ \text{rotations/sec}} = 0.4608\ \text{seconds} \approx 460.8\ \text{ms}$$

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Step 2: One rotation = 360 degrees

So, the time per degree is:

$$\frac{460.8\ \text{ms}}{360^\circ} \approx 1.28\ \text{ms/degree}$$

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✅ Answer: Approximately 1.28 milliseconds per degree at 2.17 rotations per second.

Neopixels, or WS2812B LEDs, are a popular choice for LED projects, but their refresh rate can be a limitation for Persistence of Vision (POV) displays. 

Neopixel refresh rate and POV displays

• Low refresh rate: NeoPixels have a relatively low refresh rate (around 400 Hz to 2 kHz) compared to other LED types like DotStar strips (APA102 LEDs) which offer a higher refresh rate, making them a better choice for POV displays.
• Flickering: The low refresh rate in NeoPixels can result in a "speckled" appearance in fast-moving POV displays.