FCTC Test Applying Mechanical Reasoning Questions and Answers 4 — Questions and Answers
Question 1: A belt connects a small pulley (diameter 4 inches) to a large pulley (diameter 12 inches). If the small pulley turns at 900 RPM, what is the speed of the large pulley?
- 2700 RPM
- 900 RPM
- 450 RPM
- 300 RPM (Correct answer)
Correct answer: 300 RPM
Belt-driven pulley speed is inversely proportional to diameter; 900 × (4/12) = 300 RPM.
Question 2: When water flows through a pipe that narrows from 4 inches to 2 inches in diameter, what happens to the water's velocity?
- It decreases by half
- It stays the same
- It doubles
- It quadruples (Correct answer)
Correct answer: It quadruples
By the continuity equation, velocity is inversely proportional to cross-sectional area; halving the diameter reduces area by 4×, so velocity quadruples.
Question 3: A third-class lever has the effort applied between the fulcrum and the load. Which of the following is an example of a third-class lever?
- Wheelbarrow
- Seesaw
- Fishing rod (Correct answer)
- Bottle opener
Correct answer: Fishing rod
A fishing rod is a third-class lever — the hand grips near the fulcrum (base), effort is applied in the middle, and the load (fish) is at the tip.
Question 4: Two identical blocks are connected by a rope over a frictionless pulley. Block A is on a flat surface and Block B hangs off the edge. What will happen?
- Block A slides toward the pulley
- Both blocks remain stationary
- Block B falls and pulls Block A (Correct answer)
- Block A falls off the edge
Correct answer: Block B falls and pulls Block A
Block B's weight creates an unbalanced downward force, causing it to fall and pull Block A horizontally toward the pulley.
Question 5: A screw has 20 threads per inch. How many full turns are needed to advance the screw 1 inch into a piece of wood?
- 5 turns
- 10 turns
- 20 turns (Correct answer)
- 40 turns
Correct answer: 20 turns
Each turn advances the screw one thread pitch; with 20 threads per inch, 20 full turns are needed to advance 1 inch.
Question 6: A ball rolls off a horizontal table and becomes a projectile. Which of the following is true during its flight?
- Horizontal speed increases as it falls
- Vertical speed remains constant
- Horizontal speed remains constant (Correct answer)
- Both speeds remain constant
Correct answer: Horizontal speed remains constant
With no air resistance, horizontal velocity is constant while vertical velocity increases due to gravity.
Question 7: A heavy crate sits on a rough floor. Which factor does NOT affect the friction force between the crate and the floor?
- The weight of the crate
- The surface material of the floor
- The color of the crate (Correct answer)
- The coefficient of friction
Correct answer: The color of the crate
Friction depends on the normal force (related to weight), surface materials, and coefficient of friction — color has no effect.
FCTC Test Applying Mechanical Reasoning Questions and Answers 4
A belt connects a small pulley (diameter 4 inches) to a large pulley (diameter 12 inches).
If the small pulley turns at 900 RPM, what is the speed of the large pulley?