To calculate momentum using the formula \( P = mv \), where \( m \) is mass and \( v \) is velocity, you simply multiply the mass (in kg) by the velocity (in m/s).
Given:
- Mass \( m = 9 , \text{kg} \)
- Velocity \( v = 5 , \text{m/s} \)
Calculating momentum: \[ P = mv = (9 , \text{kg}) \times (5 , \text{m/s}) = 45 , \text{kg} \cdot \text{m/s} \]
Thus, the correct expression for momentum is: \[ 45 , \text{kg} \cdot \text{m/s} = (9 , \text{kg}) \times (5 , \text{m/s}) \]
Therefore, the correct response is: 45 kg*m/s = (9 kg) (5 m/s).