What is the mechanical advantage of a lever if a load of 80 N is moved by an effort of 20 N?

Explanation

To find the mechanical advantage of a lever when a load of 80 N is moved by an effort of 20 N, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Mechanical Advantage (MA)**:
- Mechanical Advantage is defined as the ratio of the load (output force) to the effort (input force) applied to the machine.

2. **Identify the Values**:
...