FireTEAM Mechanical Aptitude Flashcards

Which of the following tools uses a wedge to perform its function?

Answer: Axe

An axe is a classic example of a tool that utilizes a wedge. Its blade is designed as a wedge, which, when driven into material like wood, applies concentrated force to split it apart. This simple machine principle allows the axe to efficiently overcome resistance and perform its cutting or splitting function.

If a pulley system has two wheels and the rope is looped around both, what is the mechanical advantage of this system?

Answer: 2

The mechanical advantage of a pulley system is generally determined by the number of rope segments directly supporting the movable load. In a system with two wheels where the rope is looped around both, there are typically two segments of rope supporting the load. This configuration effectively halves the effort required to lift the load, providing a mechanical advantage of 2.

A fire hose is connected to a hydrant. If you want to increase the water pressure from the hydrant, which of the following actions should you take?

Answer: Decrease the diameter of the hose.

According to the principle of continuity in fluid dynamics, for a constant flow rate, decreasing the cross-sectional area (diameter) of a hose will increase the velocity of the water. This increase in velocity, in turn, leads to an increase in dynamic pressure within the hose. Therefore, using a narrower hose will increase the water pressure from the hydrant.

Which gear system will make the driven gear spin faster than the driver gear?

Answer: A large driver gear connected to a small driven gear.

To make the driven gear spin faster than the driver gear, the driver gear must be larger than the driven gear. This configuration creates a gear reduction in torque but an increase in rotational speed for the smaller driven gear. Each rotation of the large driver gear causes the smaller driven gear to complete multiple rotations, thus increasing its speed.

If you use a lever to lift a heavy object and the fulcrum is closer to the load than to the effort, what happens?

Answer: The load will be easier to lift.

When the fulcrum is positioned closer to the load than to the effort, it creates a longer effort arm. This setup increases the mechanical advantage of the lever, meaning you need to apply less force (effort) over a greater distance to lift the heavy object. Consequently, the load becomes easier to lift.