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
An object weighing 50 pounds is on a frictionless inclined plane at 30 degrees. What force parallel to the plane keeps it stationary?
Answer: 25 pounds
The force parallel to the plane equals weight times sine of the angle: 50 x sin(30) = 50 x 0.5 = 25 pounds.
What is the mechanical advantage of a wheel and axle if the wheel radius is 12 inches and the axle radius is 3 inches?
Answer: 4
Mechanical advantage = wheel radius / axle radius = 12 / 3 = 4.
According to Newton's Third Law, when a rifle is fired, the recoil felt by the shooter is due to:
Answer: An equal and opposite reaction force
Newton's Third Law states every action has an equal and opposite reaction. The bullet going forward causes an equal force pushing the rifle backward.
A block and tackle pulley system has 4 supporting ropes. If the load weighs 200 pounds, what effort is theoretically required?
Answer: 50 pounds
Mechanical advantage equals the number of supporting ropes. With 4 ropes: 200 / 4 = 50 pounds of effort.
Why does a wider base make an object more stable?
Answer: It keeps the center of gravity over the base more easily
A wider base means the center of gravity can shift more before falling outside the base, making it harder to tip over.
What type of energy does a compressed spring possess?
Answer: Elastic potential energy
A compressed spring stores elastic potential energy, which can be released to do work when the spring returns to its natural shape.