WTMA Wheels, Axles, and Rotation 5

Question 1

Three gears are in a row: Gear 1 meshes with Gear 2, and Gear 2 meshes with Gear 3. All three gears have the same number of teeth. If Gear 1 rotates clockwise, which direction does Gear 3 rotate?

Accepted Answer

Clockwise

Answer

Each meshing gear reverses direction; Gear 1 (CW) → Gear 2 (CCW) → Gear 3 (CW), so Gear 3 rotates clockwise like Gear 1.

Question 2

A winch drum (axle) has a radius of 3 inches and its handle (wheel) has a radius of 18 inches. What is the mechanical advantage?

Accepted Answer

6

Answer

Mechanical advantage of a wheel-and-axle = wheel radius / axle radius = 18/3 = 6.

Question 3

A conveyor belt runs over two rollers of equal diameter. If the left roller is the drive roller turning clockwise (viewed from the front), the belt's top surface moves:

Accepted Answer

To the right

Answer

A clockwise left drive roller pulls the top of the belt toward the right, moving items on the belt surface to the right.

Question 4

Two wheels of different sizes are connected by an axle (fixed together). A rope is wrapped around the larger wheel and a load hangs from a rope on the smaller axle. When the larger wheel is turned, the load:

Accepted Answer

Rises with less input force than the load's weight

Answer

The large wheel provides mechanical advantage: input force × wheel radius = load × axle radius, so less force is needed than the load's actual weight.

Question 5

A wheel is spinning and the brake is applied to slow it down. The braking force acts at a radius of 10 inches from the center. To achieve the same stopping torque with a brake pad placed only 5 inches from the center, you would need:

Accepted Answer

Twice the braking force

Answer

Torque = Force × radius; to keep torque constant when radius is halved, force must double: F × 5 = F₀ × 10, so F = 2F₀.

WTMA - Wiesen Test of Mechanical Aptitude Practice Test

WTMA - Wiesen Test of Mechanical Aptitude Practice Test

WTMA Wheels, Axles, and Rotation 5