What’s the total system momentum before collision?

Total system momentum before collision is equal to the addition of momentum of the components of the system. Notice that momentum is a vector quantity .

The law of momentum conservation states that the total momentum of the objects before the collision is equal to the total momentum of the objects after the collision.

the answer would be a

that tool is called an altimeter which measures your altitude which can be used to tell which atmosphere you are currently in, including the stratosphere.

hope this ! : )