An object moving with a uniform velocity of 4ms-possesses kinetic energy of 120 J. Find the mass of the object.

Options

A. 15 N
B. 15 W
C. 15 kg
D. 15 Pa

Answer

To find the mass of the object given its kinetic energy and velocity, we can use the formula for kinetic energy (KE):

### Step-by-Step Solution:

1. **Write down the formula for kinetic energy**:
\[ KE = \frac{1}{2} m v^2 \]
where \( KE \) is the kinetic energy, \( m \) is the mass, and \( v \) is the velocity.

2. **Substitute the known values into the formula**:
Given:
- Kinetic Energy (KE) = 120 J
- Velocity (v) = 4 m/s

Substitute these values into the formula:
\[ 120 = \frac{1}{2} m (4)^2 \]

3. **Calculate \( v^2 \)**:
\[ (4)^2 = 16 \]
So the equation becomes:
\[ 120 = \frac{1}{2} m \cdot 16 \]

4. **Simplify the equation**:
Multiply both sides by 2 to eliminate the fraction:
\[ 240 = m \cdot 16 \]

5. **Solve for mass (m)**:
Divide both sides by 16:
\[ m = \frac{240}{16} \]
Calculate the right side:
\[ m = 15 \text{ kg} \]

### Final Answer:
The mass of the object is **15 kg**.

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