An object travels at constant speed around a circle of radius 1.0 m in 2.0 seconds. What is the magnitude of its acceleration?
Correct answer: B. π2
- A. 0
- B. π2
- C. 2 π2
- D. 4 π2
Explanation
The speed is circumference divided by time: v = 2π(1.0 m) ÷ 2.0 s = π m/s. Centripetal acceleration is a = v²/r = (π m/s)² ÷ 1.0 m = π² m/s². Students may choose zero because the speed is constant, but circular motion still has acceleration because the velocity direction changes.
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