EEI Tech Mechanical Concept Flashcards

A worm gear driving a worm wheel is commonly used because it:

Answer: Provides a large speed reduction in a compact space

Worm gears give a high gear ratio and large speed reduction in a small package.

When a moving object collides and stops, its kinetic energy is mainly converted into:

Answer: Heat, sound, and deformation

Energy is conserved and converts mostly to heat, sound, and material deformation on impact.

A container of water has a small hole near the bottom and another near the top. Water sprays out:

Answer: Faster from the bottom hole

Greater depth means greater water pressure, so the bottom hole sprays faster and farther.

Which of these increases the mechanical advantage of an inclined plane?

Answer: Making the ramp longer for the same height

A longer ramp for the same rise reduces required force, increasing mechanical advantage.

A gear train has a driver of 12 teeth meshing with a gear of 36 teeth. The torque on the driven gear, compared to the driver, is:

Answer: 3 times greater

Torque increases with the gear ratio: 36/12 = 3 times greater on the driven gear.

Why does a heavy flywheel keep spinning after the power source is removed?

Answer: Because of its rotational inertia

Inertia causes a rotating mass to continue spinning until friction slows it.

In a hydraulic brake system, why is a liquid used instead of a gas?

Answer: Liquids are nearly incompressible and transmit force instantly

Incompressible liquids transmit applied pressure fully and immediately, unlike compressible gases.