WTMA Wheels, Axles, and Rotation 2 ā Questions and Answers
Question 1: 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?
- 30 RPM
- 60 RPM
- 120 RPM (Correct answer)
- 240 RPM
Correct answer: 120 RPM
When connected by a belt, the smaller wheel spins twice as fast because RPM Ć radius is constant, so 60 Ć 10/5 = 120 RPM.
Question 2: 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?
- 1
- 2
- 4 (Correct answer)
- 5
Correct answer: 4
With meshed gears, revolutions are inversely proportional to tooth count: 20/5 = 4 revolutions for Wheel B.
Question 3: A door handle uses a spindle (axle) with a knob on each end. Turning one knob clockwise causes the other knob to rotate:
- Clockwise (Correct answer)
- Counterclockwise
- It stays still
- It oscillates
Correct answer: Clockwise
Both knobs are fixed to the same spindle, so they always rotate in the same direction simultaneously.
Question 4: A wheel of diameter 2 feet rolls along the ground without slipping. How far does it travel in 10 complete rotations?
- 20 feet
- 62.8 feet (Correct answer)
- 31.4 feet
- 6.28 feet
Correct answer: 62.8 feet
Distance = circumference Ć rotations = Ļ Ć diameter Ć 10 = Ļ Ć 2 Ć 10 ā 62.8 feet.
Question 5: Which of the following best describes mechanical advantage gained from a wheel-and-axle system?
- The axle always moves faster than the wheel
- Turning the larger wheel requires less force to overcome load on the smaller axle (Correct answer)
- The wheel and axle always rotate at the same speed
- The axle diameter must equal the wheel diameter
Correct 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.
Question 6: Wheel C turns clockwise and is belted to Wheel D. Wheel D is belted to Wheel E. In which direction does Wheel E turn?
- Counterclockwise
- Clockwise (Correct answer)
- It doesn't turn
- It alternates directions
Correct answer: Clockwise
A belt preserves rotation direction through each connection, so CāDāE all turn clockwise.
Question 7: 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:
- 200 RPM (Correct answer)
- 50 RPM
- 800 RPM
- 100 RPM
Correct answer: 200 RPM
Wheels mounted on the same rigid shaft always rotate at exactly the same RPM regardless of their sizes.
WTMA Wheels, Axles, and Rotation 2
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?