Question

Explain the following text primarily based on the surrounding page content:
A class __blanklever never has a mechanical advantage.
A class __blanklever always has a mechanical advantage.
A class __blanklever could go either way.(1 point)
Responses

1; 2; 3
1; 2; 3

2; 3; 1
2; 3; 1

2; 1; 3
2; 1; 3

3; 2; 1

Answer 1

Correct answer: 3; 2; 1

Why:
- Class 3 (third‑class) lever never has a mechanical advantage. The effort is between the fulcrum and the load, so the effort arm is always shorter than the load arm (MA < 1). Example: tweezers, most human limbs (biceps action).
- Class 2 (second‑class) lever always has a mechanical advantage. The load is between fulcrum and effort, so the effort arm is always longer than the load arm (MA > 1). Example: wheelbarrow, nutcracker.
- Class 1 (first‑class) lever can go either way. The fulcrum is between effort and load; depending on the relative distances (effort arm vs. load arm) the mechanical advantage can be >1, <1, or =1. Example: seesaw, crowbar.