FCTC Mechanical Reasoning Principles 2

Question 1

A fire pump uses a centrifugal impeller. What happens to water pressure output if the pump speed is doubled?

Accepted Answer

Pressure increases by a factor of 4

Answer

Pressure doubles

Answer

Pressure stays the same

Answer

Pressure is cut in half

Question 2

A hydraulic spreader (Jaws of Life) uses fluid to generate force. Which principle explains how a small force on the input cylinder creates a larger force on the output cylinder?

Accepted Answer

Pascal's Law

Answer

Boyle's Law

Answer

Bernoulli's Principle

Answer

Newton's Third Law

Question 3

A firefighter uses a Halligan bar as a class 1 lever to force a door. If the fulcrum is 3 inches from the load end and the firefighter applies force at 24 inches from the fulcrum, what is the mechanical advantage?

Accepted Answer

8

Answer

4

Answer

6

Answer

10

Question 4

What type of pulley system would a firefighter use to lift a victim from a below-grade confined space with the greatest mechanical advantage using a single movable pulley?

Accepted Answer

Movable pulley — 2:1

Answer

Fixed pulley — 1:1

Answer

Block and tackle — 4:1

Answer

Z-rig — 3:1

Question 5

Which type of gear arrangement is used when two gears mesh together with teeth, and turning the first gear clockwise causes the second gear to turn counterclockwise?

Accepted Answer

Spur gear

Answer

Worm gear

Answer

Planetary gear

Answer

Bevel gear

Question 6

A fire hose nozzle is attached at the end of 100 feet of hose. What happens to water velocity as the water passes through the nozzle opening (assuming nozzle diameter is smaller than hose diameter)?

Accepted Answer

Velocity increases

Answer

Velocity decreases

Answer

Velocity stays the same

Answer

Velocity becomes zero