FCTC FCTC Mechanical Reasoning Principles Questions and Answers 2 — Questions and Answers
Question 1: A gear with 20 teeth meshes with a gear with 40 teeth. If the smaller gear rotates at 100 RPM, what is the speed of the larger gear?
- 25 RPM
- 50 RPM (Correct answer)
- 200 RPM
- 400 RPM
Correct answer: 50 RPM
Gear speed is inversely proportional to tooth count, so 100 × (20/40) = 50 RPM.
Question 2: Which type of lever has the fulcrum located between the effort and the load?
- Second-class lever
- Third-class lever
- First-class lever (Correct answer)
- Compound lever
Correct answer: First-class lever
A first-class lever places the fulcrum between the effort force and the load, like a seesaw.
Question 3: A pipe with a diameter of 4 inches narrows to a diameter of 2 inches. How does the fluid velocity change?
- It decreases by half
- It stays the same
- It doubles
- It quadruples (Correct answer)
Correct answer: It quadruples
By continuity, flow area decreases by a factor of 4 (radius squared), so velocity quadruples.
Question 4: A 200-lb load is placed on one end of a lever 10 feet long. If the fulcrum is 2 feet from the load, how much effort is needed at the other end to balance it?
- 40 lb
- 50 lb (Correct answer)
- 100 lb
- 160 lb
Correct answer: 50 lb
Torque balance: 200 × 2 = effort × 8, so effort = 400/8 = 50 lb.
Question 5: Which simple machine consists of a grooved wheel with a rope or cable running along its groove?
- Wedge
- Inclined plane
- Pulley (Correct answer)
- Screw
Correct answer: Pulley
A pulley is a grooved wheel that redirects or multiplies force using a rope or cable.
Question 6: If you push a 50-lb box up a frictionless inclined plane 10 feet long that rises 2 feet, what force is required?
- 5 lb
- 10 lb (Correct answer)
- 25 lb
- 50 lb
Correct answer: 10 lb
The mechanical advantage is 10/2 = 5, so required force = 50/5 = 10 lb.
FCTC FCTC Mechanical Reasoning Principles Questions and Answers 2
A gear with 20 teeth meshes with a gear with 40 teeth.
If the smaller gear rotates at 100 RPM, what is the speed of the larger gear?