Common Misconceptions

⚠️ Common Misconceptions

Misconception 1: "At terminal velocity, there are no forces acting"

This is incorrect. At terminal velocity there are still two forces acting — weight (downward) and drag (upward). What has changed is that they are equal in size, so the resultant force is zero. The forces haven't disappeared; they've balanced out.

Misconception 2: "Terminal velocity means the object has stopped moving"

Terminal velocity is a constant velocity, not zero velocity. The object is still falling — it has simply stopped accelerating. A skydiver at terminal velocity is still travelling at 55 m/s, which is very fast indeed.

Misconception 3: "Heavier objects always fall faster"

In a vacuum (no air), all objects fall at the same rate regardless of mass (the famous Galileo result — proved on the Moon by Apollo 15). In air, heavier objects do have a higher terminal velocity, but this is because they need more drag to balance their greater weight — the effect only shows up because of air resistance.

Misconception 4: "The gradient of a distance-time graph gives acceleration"

The gradient of a distance-time graph gives speed. You need a velocity-time graph to read off acceleration from the gradient. These are two very different graphs and are frequently confused in exams.