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Q4.22: NCERT Physics - Part 1 LAWS OF MOTION 4.22 Solution: If, in Exercise 4.21, the speed of the stone is increased…
⚠️ Common Exam Traps & Conceptual Pitfalls
Students often picture the stone shooting radially outward because the centripetal force disappears, but Newton's first law dictates it keeps moving in the direction of its instantaneous velocity – the tangent to the circle – regardless of how fast it was going.
If, in Exercise 4.21, the speed of the stone is increased beyond the maximum permissible value, and the string breaks suddenly, which of the following correctly describes the trajectory of the stone after the string breaks: (a) the stone moves radially outwards, (b) the stone flies off tangentially from the instant the string breaks, (c) the stone flies off at an angle with the tangent whose magnitude depends on the speed of the particle?
Step-by-Step Verified Solution
**Answer:** (b) the stone flies off tangentially from the instant the string breaks
**Step-by-Step Explanation:**
When the string breaks, the centripetal force disappears. By Newton's first law, the stone continues in the direction of its instantaneous velocity, which is tangential to the circular path at the point of breaking [citation:7][citation:10].
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