FREE OAR Mechanical Reasoning Question and Answers Flashcards
6 cards from real OAR practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 FREE OAR Mechanical Reasoning Question and Answers flashcards as text
An inclined plane is 10 ft long and 3 ft high. What is its ideal mechanical advantage?
Answer: 3.33
IMA of an inclined plane equals length divided by height: 10/3 ≈ 3.33.
A wheel has a radius of 12 inches and its axle has a radius of 3 inches. What force must be applied to the wheel to lift a 200-lb load on the axle?
Answer: 50 lb
Mechanical advantage = wheel radius / axle radius = 12/3 = 4, so effort = 200/4 = 50 lb.
A 50-kg object moves at 10 m/s. What is its kinetic energy?
Answer: 2500 J
KE = ½mv² = ½ × 50 × 10² = 2500 J.
Two springs with constants of 40 lb/in and 60 lb/in are connected in parallel. What is the combined spring constant?
Answer: 100 lb/in
In parallel, spring constants add directly: 40 + 60 = 100 lb/in.
A cam rotates and pushes a flat follower upward 0.5 inches during 180 degrees of rotation. What is the total follower displacement for one full cam revolution?
Answer: 0.5 in
The follower rises 0.5 in during the first half-turn and returns to its starting position during the second half, so total displacement is 0.5 in at peak.
A 100-lb force is applied at a 30-degree angle above the horizontal to push a cart. What is the horizontal component of the force?
Answer: 86.6 lb
The horizontal component equals 100 × cos(30°) = 100 × 0.866 = 86.6 lb.