In kinematics (Class 9 and 11 Physics), understanding the difference between distance and displacement is crucial. A classic problem involves an object moving along a circular path of radius $r$.
Distance is a scalar quantity (path-dependent).
Displacement is a vector quantity (shortest straight-line path).
In circular motion, displacement can be zero, but distance will never be zero.
If the object starts at point A and travels all the way around the circle back to point A:
If the object travels exactly halfway around the circle (from point A to point B on the opposite side):
Using the Pythagorean theorem, the straight line connecting two points at a 90-degree angle on the circle is √(r² + r²) = r√2.
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