Mechanical Aptitude Test Mechanical Aptitude Levers, Pulleys, and Gears 1

Question 1

A lever has its fulcrum 2 feet from the load and 6 feet from the effort. If a 90-pound load is placed on the short end, how much effort is required to lift it?

Accepted Answer

30 pounds

Answer

Using the lever principle: Effort × effort arm = Load × load arm. So Effort × 6 = 90 × 2, giving Effort = 180 ÷ 6 = 30 pounds. The 3:1 mechanical advantage means one-third the force is needed.

Question 2

A fixed pulley attached to a ceiling is used to lift a 150-pound box. Ignoring friction, how much force must be applied to the rope?

Accepted Answer

150 pounds

Answer

A single fixed pulley only changes the direction of force — it provides no mechanical advantage. You must still exert a force equal to the full weight of the load, which is 150 pounds.

Question 3

A movable pulley is combined with a fixed pulley to create a simple block-and-tackle system. What is the mechanical advantage of this two-pulley arrangement?

Accepted Answer

2

Answer

In a block-and-tackle with one fixed and one movable pulley, two rope segments support the movable pulley and its load, giving a mechanical advantage of 2. This means you lift with half the force the load weighs.

Question 4

Gear A has 15 teeth and meshes with Gear B, which has 45 teeth. If Gear A is the driver and turns at 600 RPM, in which direction does Gear B turn and at what speed?

Accepted Answer

Opposite direction to A, at 200 RPM

Answer

Meshed gears always rotate in opposite directions. The gear ratio is 15:45 = 1:3, so Gear B turns at 600 ÷ 3 = 200 RPM. The larger gear turns slower and in the reverse direction.

Question 5

A first-class lever is 10 feet long. The fulcrum is placed 4 feet from the effort end. Where is the fulcrum relative to the load end, and what is the mechanical advantage?

Accepted Answer

6 feet from load; MA = 1.5

Answer

If the lever is 10 feet long and the fulcrum is 4 feet from the effort, it is 6 feet from the load. Mechanical advantage = effort arm ÷ load arm = 4 ÷ 6 ≈ 0.67... wait — MA = load arm / effort arm is incorrect here. MA = effort arm / load arm = 6/4 = 1.5. The effort arm is the distance from effort to fulcrum (6 ft) and load arm is fulcrum to load (4 ft), giving MA = 6 ÷ 4 = 1.5.

Mechanical Aptitude Test Practice Test

Mechanical Aptitude Test Practice Test

Mechanical Aptitude Test Mechanical Aptitude Levers, Pulleys, and Gears 1