4. Which of the following objects has the momentum with the greatest magnitude? A 9-kg mass moving at 3m/s B. A 12-kg mass moving at 1m/s C. A 5-kg mass moving at 2m/s D. A4-kg mass moving at 4m/s

To determine which object has the momentum with the greatest magnitude, we need to calculate the momentum for each object and compare them.<br /><br />Momentum is defined as the product of an object's mass and its velocity. The formula for momentum is:<br /><br />\[ \text{momentum} = \text{mass} \times \text{velocity} \]<br /><br />Let's calculate the momentum for each object:<br /><br />A. For a 9-kg mass moving at 3 m/s:<br />\[ \text{momentum} = 9 \, \text{kg} \times 3 \, \text{m/s} = 27 \, \text{kg} \cdot \text{m/s} \]<br /><br />B. For a 12-kg mass moving at 1 m/s:<br />\[ \text{momentum} = 12 \, \text{kg} \times 1 \, \text{m/s} = 12 \, \text{kg} \cdot \text{m/s} \]<br /><br />C. For a 5-kg mass moving at 2 m/s:<br />\[ \text{momentum} = 5 \, \text{kg} \times 2 \, \text{m/s} = 10 \, \text{kg} \cdot \text{m/s} \]<br /><br />D. For a 4-kg mass moving at 4 m/s:<br />\[ \text{momentum} = 4 \, \text{kg} \times 4 \, \text{m/s} = 16 \, \text{kg} \cdot \text{m/s} \]<br /><br />Comparing the momenta, we can see that the momentum with the greatest magnitude is 27 kg·m/s, which corresponds to option A.<br /><br />Therefore, the correct answer is A.