Question

# your roommate is working on his bicycle and has the bike upside down. he spins the 70.0 cm -diameter wheel, and you notice that a pebble stuck in the tread goes by three times every second.

Answer

6.6 meters/second

- Convert the diameter of the wheel to meters. A: The diameter of the wheel is 70.0 cm, which is equal to 0.7 meters.
- Calculate the circumference of the wheel. A: The circumference of the wheel is equal to pi times the diameter, or 2.2 meters.
- Calculate the distance the pebble travels in one revolution. A: The distance the pebble travels in one revolution is equal to the circumference of the wheel, or 2.2 meters.
- Multiply the distance traveled by the frequency of revolutions. A: The speed of the pebble is equal to the distance traveled in one revolution multiplied by the frequency of revolutions, or (2.2 meters/rev) x (3 rev/s) = 6.6 meters/second.