Question

in the 1960s nasa designed a rocket (the sea dragon) to be launched from underwater. the rocket was never built, but lets imagine it was. at some point as the rocket rises, it hits sea level (elevation: 0 meters). thats when we start our stopwatch. lets assume that in the first seconds the rockets elevation is changing at a rate of 25 m/s. the rate is because the rocket is < positive negative >.

Explanation:

Step1: Define upward direction

The upward - movement of the rocket is considered. Since the rocket is rising (going upwards), and the rate of change of its elevation is given as 25 m/s which indicates an increase in elevation with time.

Step2: Determine sign convention

In physics, when an object moves in the upward direction, the rate of change of its vertical position (elevation) is positive.

Answer:

positive