Two forces of 45 kg-f and 40 kg-f act on a body In opposite directions. What Is the resultant force ?

Options

A. 45 kg-f
B. 40 kg-f
C. 5 kg-f
D. 90 kg-f.

Explanation

To solve the problem of finding the resultant force when two forces act in opposite directions, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Forces**: We have two forces acting on the body:
- Force 1 (F1) = 45 kg-f (acting in one direction)
- Force 2 (F2) = 40 kg-f (acting in the opposite direction)

2. **Determine the Direction**: Since the forces are acting in opposite directions, we can consider one force as positive and the other as negative. For example:
- F1 = +45 kg-f
- F2 = -40 kg-f

3. **Calculate the Resultant Force**: The resultant force (F_net) can be calculated by taking the difference between the two forces:
\[ F_{net} = F1 - F2 \]
Substituting the values:
\[ F_{net} = 45 \, \text{kg-f} - 40 \, \text{kg-f} = 5 \, \text{kg-f} \]

4. **Conclusion**: The resultant force acting on the body is 5 kg-f. Since the force is positive, it indicates that the net force is in the direction of the larger force (45 kg-f).

### Final Answer:
The resultant force is **5 kg-f**.

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