Test Pulleys, Gears, and Levers Questions and Answers Flashcards

A compound pulley system uses 4 rope segments supporting a load. If the load weighs 400 lbs, how much force must be applied to lift it (ignoring friction)?

Answer: 100 lbs

With 4 supporting rope segments, the mechanical advantage is 4, so the effort needed is 400 ÷ 4 = 100 lbs.

Two gears are meshed together. Gear A has 30 teeth and Gear B has 10 teeth. If Gear A makes 2 full rotations, how many rotations does Gear B complete?

Answer: 6

The gear ratio is 30:10 = 3:1, so Gear B rotates 3 times for every rotation of Gear A, giving 2 × 3 = 6 rotations.

A firefighter uses a third-class lever to swing a pick-head axe. Where is the effort force applied on a third-class lever?

Answer: Between the fulcrum and the load

In a third-class lever, the effort is applied between the fulcrum and the load, trading mechanical advantage for speed and range of motion.

A fixed pulley changes the direction of the rope. What is its mechanical advantage?

Answer: 1

A single fixed pulley has a mechanical advantage of 1; it only redirects the force, not multiplying it.

Gear X rotates clockwise and is meshed directly with Gear Y. In which direction does Gear Y rotate?

Answer: Counterclockwise

When two gears are meshed directly, they rotate in opposite directions; if X is clockwise, Y is counterclockwise.

A first-class lever has a 60 lb load 2 feet from the fulcrum. How much effort is needed at 6 feet from the fulcrum on the other side?

Answer: 20 lbs

Using the lever equation: Effort × 6 ft = 60 lbs × 2 ft, so Effort = 120 ÷ 6 = 20 lbs.

Which of the following is an example of a second-class lever?

Answer: A wheelbarrow

A wheelbarrow is a second-class lever because the load is between the fulcrum (wheel axle) and the effort (handles).