Question

a class _lever never has a mechanical advantage. a class _lever always has a mechanical advantage. a class _lever could go either way. (1 point) 2; 1; 3 1; 2; 3 3; 2; 1 2; 3; 1

Explanation:

• Class 3 levers: The effort is between the fulcrum and the load. The effort arm is always shorter than the load arm, so they never have a mechanical advantage (mechanical advantage \(MA=\frac{\text{Load arm}}{\text{Effort arm}}\), and since effort arm \( < \) load arm, \(MA<1\)).
• Class 2 levers: The load is between the fulcrum and the effort. The load arm is always shorter than the effort arm. So, \(MA = \frac{\text{Load arm}}{\text{Effort arm}}> 1\) (always has a mechanical advantage).
• Class 1 levers: The fulcrum is between the effort and the load. Depending on the position of the fulcrum, the effort arm can be longer than the load arm (\(MA>1\)), equal to the load arm (\(MA = 1\)) or shorter than the load arm (\(MA<1\)). So, it could go either way.

Answer:

3; 2; 1