The energy of a particle moving at 5 m/s is 125 J. The mass is

Options

A. 4kg
B. 6 kg
C. 10 kg
D. 25 kg

Answer

To find the mass of a particle given its energy and velocity, we can use the formula for kinetic energy:

\[ E = \frac{1}{2} m v^2 \]

Where:
- \( E \) is the kinetic energy,
- \( m \) is the mass,
- \( v \) is the velocity.

### Step-by-Step Solution:

1. **Identify the given values:**
- Energy \( E = 125 \, \text{J} \)
- Velocity \( v = 5 \, \text{m/s} \)

2. **Substitute the values into the kinetic energy formula:**
\[ 125 = \frac{1}{2} m (5)^2 \]

3. **Calculate \( v^2 \):**
\[ 5^2 = 25 \]

4. **Rewrite the equation with the calculated value:**
\[ 125 = \frac{1}{2} m \cdot 25 \]

5. **Multiply both sides by 2 to eliminate the fraction:**
\[ 250 = m \cdot 25 \]

6. **Solve for \( m \) by dividing both sides by 25:**
\[ m = \frac{250}{25} \]

7. **Calculate the mass:**
\[ m = 10 \, \text{kg} \]

### Final Answer:
The mass of the particle is **10 kg**.