How do i come to the conclusion that the previous equation is the answer

Explanation:

Velocity is the first derivative of position with respect to time.  So for each option, the velocity is:

v = 3t² + 2

v = 2t − 2

v = 1

v = -2t

At some point in time, v = 0.  It can't be the first option, which is always positive.  It can't be the third option, which is always 1.  And it can't be the fourth option, which is always negative.

Only the second option has a velocity that can be 0 (at t = 1).

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 ! : )