What is the momentum of an object that has a mass of two kilograms and moves at a constant velocity of three metres per second?
Okay, so to answer this question, we need to recall that the momentum of an object, which we’ll call 𝑃, is defined as the mass of the object multiplied by the velocity of the object. The object is moving at a constant velocity as we’ve been told it is. And it has a constant mass. In other words, the mass of the object is not changing, which it doesn’t seem to be cause we’ve been told it’s two kilograms.
Then, the object has a constant momentum. So the momentum of this object, which we call 𝑃, is equal to the mass of this object, two kilograms multiplied by three metres per second. That’s the velocity of the object. At which one, we can evaluate two times three and see that the units of momentum are kilograms times metres per second or, in other words, kilogram metres per second. And hence, we can say that the momentum of the object is six kilogram metres per second. We place this little dot here to signify multiplication when multiplying kilograms by metres per second to give us the units of momentum.
And hence, our final answer is that the momentum of the object is six kilograms metres per second.