Mechanical Comprehension Flashcards
6 cards from real AFCT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Mechanical Comprehension flashcards as text
A lever has a fulcrum placed 2 feet from a 100-pound load and 8 feet from the effort. What effort force is needed to lift the load?
Answer: 25 pounds
Using the lever principle: Load x load arm = Effort x effort arm. So 100 x 2 = Effort x 8, giving Effort = 25 pounds.
Which simple machine is a screw most closely related to?
Answer: Inclined plane
A screw is essentially an inclined plane wrapped around a cylinder, converting rotational force into linear motion.
If two gears are meshed together, what can be said about their rotation?
Answer: They rotate in opposite directions
When two gears mesh directly, they always rotate in opposite directions because the teeth of one push the teeth of the other.
What happens to water pressure as depth increases?
Answer: It increases
Water pressure increases with depth because the weight of the water above pushes down, adding to the pressure at lower levels.
A fixed pulley is primarily used to:
Answer: Change the direction of force
A single fixed pulley changes the direction of the applied force but does not provide a mechanical advantage.
What principle explains why a hydraulic jack can lift a heavy vehicle with a small force?
Answer: Pascal's Law
Pascal's Law states that pressure applied to a confined fluid is transmitted equally in all directions, allowing a small force on a small piston to create a large force on a larger piston.