A resultant force of 45 kgf is acting on a body whose acceleration is 10 `"m/ sec"^2` . Calculate the mass of the body.

Options

A. 450 kg
B. 44.1 kg
C. 4.5 kg
D. 1960 kg.

Explanation

To solve the problem step by step, we will use Newton's second law of motion, which states that the resultant force acting on an object is equal to the mass of the object multiplied by its acceleration (F = m * a).

### Step-by-Step Solution:

1. **Identify the Given Values:**
- Resultant Force (F) = 45 kgf
- Acceleration (a) = 10 m/s²

2. **Convert the Force from kgf to Newtons:**
- We know that 1 kgf is equivalent to the force exerted by gravity on a mass of 1 kg, which is approximately 9.8 N.
- Therefore, to convert 45 kgf to Newtons:
\[ F = 45 \, \text{kgf} \times 9.8 \, \text{N/kgf} = 441 \, \text{N} \]

3. **Use Newton's Second Law to Find the Mass:**
- According to Newton's second law, \( F = m \cdot a \).
- Rearranging the formula to find mass (m):
\[ m = \frac{F}{a} \]
- Substitute the values of F and a:
\[ m = \frac{441 \, \text{N}}{10 \, \text{m/s}^2} = 44.1 \, \text{kg} \]

4. **Conclusion:**
- The mass of the body is 44.1 kg.

### Final Answer:
The mass of the body is **44.1 kg**.

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