CPS FREE CPS Firefighter Test Mechanical Aptitude Principles Questions and Answers 2 — Questions and Answers
Question 1: A firefighter uses a Class 2 lever to lift a heavy hose bundle. The fulcrum is at one end, the load is in the middle, and the effort is applied at the other end. Compared to a Class 1 lever, this arrangement:
- Multiplies force but reduces speed (Correct answer)
- Reduces force but increases speed
- Always provides a mechanical advantage greater than 1
- Provides no mechanical advantage
Correct answer: Multiplies force but reduces speed
In a Class 2 lever the load is between the fulcrum and effort, so the effort arm is always longer than the load arm, giving a mechanical advantage greater than 1 and multiplying force.
Question 2: Water flows through a 4-inch diameter supply hose into a 2-inch diameter attack hose. According to the continuity principle, the water speed in the attack hose will be:
- Half the speed in the supply hose
- The same speed as in the supply hose
- Four times the speed in the supply hose (Correct answer)
- Twice the speed in the supply hose
Correct answer: Four times the speed in the supply hose
When diameter halves, the cross-sectional area decreases by a factor of 4, so the fluid must travel 4 times faster to maintain the same flow rate.
Question 3: A hydraulic jack used to lift a vehicle has a small input piston with an area of 2 in² and a large output piston with an area of 20 in². If 50 lb of force is applied to the input piston, the output force is:
- 5 lb
- 100 lb
- 500 lb (Correct answer)
- 1,000 lb
Correct answer: 500 lb
Pascal's Law states that pressure is equal throughout the fluid, so output force = input force × (output area / input area) = 50 × (20/2) = 500 lb.
Question 4: A firefighter pulls a rope over a single fixed pulley to raise a 200 lb object. Ignoring friction, the effort force required is:
- 50 lb
- 100 lb
- 200 lb (Correct answer)
- 400 lb
Correct answer: 200 lb
A single fixed pulley only changes the direction of force; it does not provide mechanical advantage, so the effort equals the load.
Question 5: Two gears are meshed together. Gear A has 12 teeth and Gear B has 36 teeth. If Gear A rotates at 120 RPM, Gear B rotates at:
- 360 RPM
- 40 RPM (Correct answer)
- 120 RPM
- 10 RPM
Correct answer: 40 RPM
Gear speed is inversely proportional to tooth count, so Gear B RPM = 120 × (12/36) = 40 RPM.
Question 6: A firefighter on a ladder feels the rungs getting hotter as she climbs toward the roof. This heat transfer from rung to rung through the metal ladder is best described as:
- Convection
- Radiation
- Conduction (Correct answer)
- Evaporation
Correct answer: Conduction
Conduction is the transfer of heat through direct contact between molecules in a solid material, such as metal ladder rungs.
CPS FREE CPS Firefighter Test Mechanical Aptitude Principles Questions and Answers 2
A firefighter uses a Class 2 lever to lift a heavy hose bundle.
The fulcrum is at one end, the load is in the middle, and the effort is applied at the other end.
Compared to a Class 1 lever, this arrangement: