Question

(b) a blimp floats in the same place for a long time.

Explanation:

Step1: Analyze the first graph

The first graph shows an increasing trend in altitude over time, which does not represent floating in the same place.

Step2: Analyze the second graph

The second graph shows a decreasing trend in altitude over time, which does not represent floating in the same place.

Step3: Analyze the third graph

The third graph shows a constant altitude over time. When an object (in this case, the blimp) has a constant altitude, it means it is not ascending (increasing altitude) or descending (decreasing altitude), so it is floating in the same place.

Step4: Analyze the fourth graph

The fourth graph has a vertical line. A vertical line in a time - altitude graph implies an undefined slope (infinite rate of change), which is not a physical situation for altitude over time.

Answer:

The third graph (the one with a constant altitude over time) is the correct representation.