Mechanical Aptitude Levers, Pulleys, and Gears Flashcards
7 cards from real MECHANICAL APTITUDE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Mechanical Aptitude Levers, Pulleys, and Gears flashcards as text
Three gears are in a line: A drives B, B drives C. If A and C have 30 teeth and B has 15 teeth, which direction does C rotate compared to A?
Answer: Same direction
With an odd number of meshed gears in a line, the first and last gears rotate in the same direction; the middle gear is an idler.
A movable pulley is attached to the load. How does this affect the effort required to lift the load?
Answer: Halves the effort needed
A single movable pulley provides a mechanical advantage of 2, meaning you only need half the force to lift the load.
A seesaw with two children is balanced. Child A (60 lbs) sits 4 feet from the fulcrum. Where must Child B (80 lbs) sit to maintain balance?
Answer: 3 feet from fulcrum
For balance, torques must be equal: 60 × 4 = 80 × d, so d = 240 ÷ 80 = 3 feet.
Which type of gear is used to transmit power between shafts at a 90-degree angle?
Answer: Bevel gears
Bevel gears have angled teeth cut on a conical surface, making them ideal for transmitting rotation between perpendicular shafts.
In a block-and-tackle system, increasing the number of pulleys primarily:
Answer: Increases the distance through which effort must be applied
Greater mechanical advantage means less force is needed, but the effort rope must be pulled a proportionally greater distance.
A lever has a mechanical advantage of 5. If the load weighs 200 pounds, how much effort is required (ignoring friction)?
Answer: 40 lbs
Effort = Load ÷ Mechanical Advantage = 200 ÷ 5 = 40 lbs.
A rack-and-pinion gear system converts:
Answer: Rotational motion to linear motion
A rack-and-pinion converts the pinion gear's rotational motion into the straight-line (linear) motion of the rack.