Calculate the angle between a 20 N force and a 30 N force so that their resultant is 40 N

Explanation

To solve the problem of finding the angle between a 20 N force and a 30 N force such that their resultant is 40 N, we can use the law of cosines for vectors. Here’s a step-by-step solution:

### Step 1: Understand the Problem
We have two forces:
- \( F_1 = 20 \, \text{N} \)
- \( F_2 = 30 \, \text{N} \)

And their resultant force \( R = 40 \, \text{N} \). We need to find the angle \( \theta \) between these two forces.
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