ASVAB (Armed Services Vocational Aptitude Battery)Mechanical Comprehension (MC)Easy
A worker uses a lever to lift a heavy crate. If the fulcrum is placed closer to the crate, what effect will this have on the force required to lift the crate?
- AThe force required will remain the same.
- BThe direction of the force will reverse.
- CThe force required will decrease.
- DThe force required will increase.
Show answer & explanationAnswer & explanation
Correct answer: C. The force required will decrease.
Moving the fulcrum closer to the load (the crate) increases the mechanical advantage of the lever. This means a smaller input force is needed over a greater distance to move the load.
Why the other options are wrong
- A. This is incorrect; changing the fulcrum's position alters the mechanical advantage.
- B. This is incorrect; the direction of force is determined by how the lever is operated, not the fulcrum's position relative to the load.
- D. This is incorrect; moving the fulcrum closer to the load decreases the required force.
Lever Mechanical Advantage
The ratio of the output force to the input force in a lever system, indicating how much a lever multiplies the applied force.
- Mechanical advantage = Output Force / Input Force
- Mechanical advantage = Distance from fulcrum to effort / Distance from fulcrum to load
- Moving the fulcrum closer to the load increases mechanical advantage.
Memory trick: Levers Make Awesome Gains, Effortlessly!