Velocity is calculated by diameter of wheel x Pi x PRM.

• A. False
• B. Pi times diameter divided by RPM
• C. Pi times diameter times RPM
• D. RPM divided by Pi times diameter

Answer: (C)

The main idea is that velocity of a rolling wheel comes from how far it travels each revolution. Each revolution covers the wheel’s circumference, which is π times the diameter. If the wheel makes RPM revolutions per minute, the distance traveled per minute is circumference per revolution times revolutions per minute. So velocity = (π × diameter) × RPM. This matches the expression pi times diameter times RPM, so that form is correct.

Using division by RPM would imply speed decreases as RPM increases, which doesn’t reflect distance traveled per minute. Dividing by (π × diameter) would yield an incorrect, much smaller value and doesn’t match the units of velocity. If you need per-second velocity instead of per-minute, you’d convert RPM to revolutions per second by dividing by 60, giving velocity = π × diameter × (RPM/60).