Concept:Centripetal acceleration is a vector quantity. Even if an object's speed is constant, moving in a circle means its direction of motion is continuously changing, so the acceleration direction changes as well.
Formula:$$ |\vec{a}_c| = \frac{v^2}{r} $$
Solution:- Since speed \( v \) and radius \( r \) are constant, the magnitude of acceleration \( \frac{v^2}{r} \) remains perfectly constant.
- However, centripetal acceleration always points toward the center. As the car moves along the track, the absolute spatial direction of 'toward the center' continuously rotates.
- Therefore, it has a constant magnitude but varying direction.
Why other options are incorrect:- Option A is wrong because circular motion requires acceleration to change the velocity vector's direction.
- Option C is mathematically impossible for circular motion.
- Option D is incorrect because the magnitude remains constant.
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