Wheels, Axles, and Rotation Flashcards

A wheel with a radius of 10 inches is connected by a belt to a wheel with a radius of 5 inches. If the larger wheel rotates at 60 RPM, how fast does the smaller wheel rotate?

Answer: 120 RPM

When connected by a belt, the smaller wheel spins twice as fast because RPM × radius is constant, so 60 × 10/5 = 120 RPM.

Two wheels are meshed (teeth interlocked). Wheel A has 20 teeth and Wheel B has 5 teeth. If Wheel A makes 1 full revolution, how many revolutions does Wheel B make?

Answer: 4

With meshed gears, revolutions are inversely proportional to tooth count: 20/5 = 4 revolutions for Wheel B.

A door handle uses a spindle (axle) with a knob on each end. Turning one knob clockwise causes the other knob to rotate:

Answer: Clockwise

Both knobs are fixed to the same spindle, so they always rotate in the same direction simultaneously.

A wheel of diameter 2 feet rolls along the ground without slipping. How far does it travel in 10 complete rotations?

Answer: 62.8 feet

Distance = circumference × rotations = π × diameter × 10 = π × 2 × 10 ≈ 62.8 feet.

Which of the following best describes mechanical advantage gained from a wheel-and-axle system?

Answer: Turning the larger wheel requires less force to overcome load on the smaller axle

A large wheel provides mechanical advantage by allowing a small input force over a large radius to overcome a larger load at the smaller axle radius.

Wheel C turns clockwise and is belted to Wheel D. Wheel D is belted to Wheel E. In which direction does Wheel E turn?

Answer: Clockwise

A belt preserves rotation direction through each connection, so C→D→E all turn clockwise.

An axle connects a small drive wheel (radius 2 in) directly to a larger output wheel (radius 8 in) on the same shaft. If the drive wheel turns at 200 RPM, the output wheel turns at:

Answer: 200 RPM

Wheels mounted on the same rigid shaft always rotate at exactly the same RPM regardless of their sizes.