Physics

Problem

A body starts from rest and attains a velocity of

30\,\text{m/s}

3\,\text{s}

while falling freely. Using the area under the velocity–time graph, the displacement covered in these

3\,\text{s}

is a)

90\,\text{m}

45\,\text{m}

60\,\text{m}

135\,\text{m}

Intuitive explanation

The key insight is that displacement isn't just about the final velocity—it's the total area trapped under the $v$ – $t$ curve. Since the body starts from rest and accelerates uniformly, the graph forms a triangle, and you can find displacement by calculating that geometric area rather than memorizing a kinematic formula. This approach works for any motion and builds intuition about what velocity over time really represents.

Intuitive explanation

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