AFCT Mechanical Comprehension 2

Question 1

A lever has a fulcrum placed 2 feet from a 100-pound load and 8 feet from the effort. What effort force is needed to lift the load?

Accepted Answer

25 pounds

Answer

Using the lever principle: Load x load arm = Effort x effort arm. So 100 x 2 = Effort x 8, giving Effort = 25 pounds.

Question 2

Which simple machine is a screw most closely related to?

Accepted Answer

Inclined plane

Answer

A screw is essentially an inclined plane wrapped around a cylinder, converting rotational force into linear motion.

Question 3

If two gears are meshed together, what can be said about their rotation?

Accepted Answer

They rotate in opposite directions

Answer

When two gears mesh directly, they always rotate in opposite directions because the teeth of one push the teeth of the other.

Question 4

What happens to water pressure as depth increases?

Accepted Answer

It increases

Answer

Water pressure increases with depth because the weight of the water above pushes down, adding to the pressure at lower levels.

Question 5

A fixed pulley is primarily used to:

Accepted Answer

Change the direction of force

Answer

A single fixed pulley changes the direction of the applied force but does not provide a mechanical advantage.

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