FCTC Test Pulleys, Gears, and Levers Questions and Answers Flashcards

If you double the length of the effort arm of a lever while keeping the resistance arm the same, what happens to the mechanical advantage?

Answer: It doubles

Since MA = effort arm ÷ resistance arm, doubling the effort arm doubles the mechanical advantage.

A block-and-tackle system has 3 movable pulleys. Approximately how many rope segments support the load?

Answer: 6

Each movable pulley adds 2 supporting rope segments, so 3 movable pulleys create 6 supporting segments.

In a gear system, which gear rotates faster — the one with more teeth or fewer teeth?

Answer: Fewer teeth

The gear with fewer teeth rotates faster because fewer teeth must mesh per revolution of the larger gear.

A pair of scissors is an example of which type of simple machine?

Answer: First-class lever

Scissors are first-class levers because the fulcrum (pivot) is between the effort (handles) and the load (blades cutting).

A movable pulley has a mechanical advantage of 2. If the load is 300 lbs, how far must the effort rope be pulled to raise the load 1 foot?

Answer: 2 feet

When MA = 2, the effort distance is twice the load distance, so you must pull 2 feet of rope to lift the load 1 foot.

What term describes the ratio of output force to input force in a simple machine?

Answer: Mechanical advantage

Mechanical advantage is defined as the ratio of output (resistance) force to input (effort) force.

A rack and pinion converts which type of motion?

Answer: Linear to rotary (or vice versa)

A rack and pinion converts rotational motion of the pinion gear into linear motion of the rack, or vice versa.