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Q3.14: NCERT Physics - Part 1 MOTION IN A PLANE 3.14 Solution: A stone tied to the end of a string 80 cm long is whirled in a…
⚠️ Common Exam Traps & Conceptual Pitfalls
Students often substitute $a=\omega r$ instead of the correct $a=\omega^{2}r$, forgetting to square the angular speed. Always write the centripetal formula as $a_c=\omega^{2}r$ (or $v^{2}/r$) after converting the radius to metres and computing $\omega=2\pi f$.
A stone tied to the end of a string 80 cm long is whirled in a horizontal circle with a constant speed. If the stone makes 14 revolutions in 25 s, what is the magnitude and direction of acceleration of the stone?
Step-by-Step Verified Solution
**Answer:** a = 9.9 m/s_, directed toward the centre.
**Step-by-Step Explanation:**
r = 0.8 m, f = 14/25 = 0.56 Hz, _ = 2�f = 3.52 rad/s.
a = __r = (3.52)_ _ 0.8 = 9.9 m/s_, toward the centre.
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