Mechanical Comprehension Flashcards

A 2:1 roping arrangement in a traction elevator means:

Answer: The cab moves at half the speed of the rope

In 2:1 roping, the rope travels twice the distance the cab moves, so cab speed is half the rope speed but the tension in the ropes is halved.

Kinetic energy is defined as:

Answer: Energy due to an object's motion

Kinetic energy (KE = ½mv²) is the energy an object possesses because of its velocity.

Guide rails in an elevator hoistway serve to:

Answer: Keep the cab and counterweight aligned during travel

Guide rails constrain lateral movement of the cab and counterweight, keeping them aligned and stable throughout travel.

Pascal's Law states that pressure applied to an enclosed fluid:

Answer: Is transmitted equally in all directions

Pascal's Law: pressure exerted on a confined fluid is transmitted undiminished in all directions throughout the fluid.

Which type of rope construction is most commonly used for elevator hoisting ropes?

Answer: Independent wire rope core (IWRC)

IWRC wire ropes have superior resistance to crushing and maintain their shape under load, making them the standard for elevator hoisting.

A pump delivers 5 gallons per minute at 1,000 psi. If pressure drops to 500 psi, what happens to flow rate (assuming constant pump power)?

Answer: Flow rate increases to 10 GPM

At constant power (P = Flow × Pressure), halving pressure doubles flow rate: 5 GPM × (1000/500) = 10 GPM.

Torsion in a shaft refers to:

Answer: Twisting force that tends to rotate one end relative to the other

Torsion is the twisting action in a shaft caused by an applied torque, creating shear stress in the material.