Mechanical Aptitude and Principles Flashcards

When two gears of equal size and equal tooth count are meshed together, the driven gear will:

Answer: Rotate at the same speed as the drive gear

Two meshing gears with equal tooth counts rotate at the same speed but in opposite directions.

A compression spring has a spring constant of 50 lbs/inch and is compressed 2 inches from its natural length. What force is required?

Answer: 100 lbs

Using Hooke's Law, force = spring constant × displacement: 50 lbs/inch × 2 inches = 100 lbs.

Torque is best defined as:

Answer: A rotational force that causes or tends to cause rotation about an axis

Torque is a rotational force (moment) that causes an object to rotate around an axis, commonly measured in foot-pounds or Newton-meters.

If you double the pressure in a pneumatic system while keeping the piston area the same, the output force will:

Answer: Double

Since Force = Pressure × Area, doubling the pressure while area stays constant directly doubles the output force.

Which type of friction acts between two surfaces that are moving (sliding) against each other?

Answer: Kinetic friction

Kinetic (sliding) friction is the resistive force acting between surfaces that are in relative motion against each other.

A belt drive has a drive pulley of 4-inch diameter running at 900 RPM and a driven pulley of 12-inch diameter. What is the speed of the driven pulley?

Answer: 300 RPM

Belt speed is constant, so the driven pulley with 3× the diameter rotates at 1/3 the speed: 900 ÷ 3 = 300 RPM.

The center of gravity of an object is best described as:

Answer: The point where the object's weight is balanced equally in all directions

The center of gravity is the point where the total weight of the object is considered to act, with mass distributed evenly in all directions from that point.