Understanding motion becomes much easier once you truly understand velocity–time graphs.
In this lesson, we look at a velocity–time graph that starts from rest, increases steadily, levels out for a while, accelerates again, and finally slows down. The key question we answer is:
👉 At which part of the graph is the acceleration zero?
To understand this, you need to remember one important idea:
Acceleration is not about speed, it is about change in velocity.
When an object starts from rest and its velocity increases, it is accelerating.
When the velocity keeps increasing upward, the acceleration is positive.
When the velocity starts reducing, the acceleration becomes negative.
But there is one special situation students often miss.
🔹 When velocity remains constant, even if the object is still moving,
🔹 there is no change in velocity,
🔹 and that means the acceleration is zero.
On the velocity–time graph, this happens at the flat or horizontal part of the graph.
That flat region shows motion at steady speed, and that is why the correct option lies there.
This concept appears repeatedly in Physics exams, including GCSE, WAEC, NECO, AP Physics, SAT, and introductory university mechanics.
📌 Watch till the end to fully understand:
👉 How to read velocity–time graphs
👉 How to identify zero acceleration correctly
👉 How to avoid common exam traps
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