A force of 50 N acts on a body of mass 10 kg at rest. Its velocity after 5 seconds if the same force acts, is

Options

A. 15m/s
B. 20m/s
C. 25 m/s
D. 30 m/s

Answer

To solve the problem step by step, we will follow the principles of Newton's laws of motion.

### Step 1: Identify the given values
- Force (F) = 50 N
- Mass (m) = 10 kg
- Initial velocity (u) = 0 m/s (since the body is at rest)
- Time (t) = 5 seconds

### Step 2: Calculate the acceleration
According to Newton's second law of motion, the acceleration (a) can be calculated using the formula:
\[ a = \frac{F}{m} \]
Substituting the values:
\[ a = \frac{50 \, \text{N}}{10 \, \text{kg}} = 5 \, \text{m/s}^2 \]

### Step 3: Use the equation of motion to find the final velocity
We will use the first equation of motion:
\[ v = u + at \]
Where:
- \( v \) = final velocity
- \( u \) = initial velocity
- \( a \) = acceleration
- \( t \) = time

Substituting the known values:
\[ v = 0 \, \text{m/s} + (5 \, \text{m/s}^2 \times 5 \, \text{s}) \]
\[ v = 0 + 25 \, \text{m/s} \]
\[ v = 25 \, \text{m/s} \]

### Final Answer
The velocity of the body after 5 seconds is **25 m/s**.

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