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Physics · PYQ NEET UG 2019(2)
हिन्दीAn object of mass 500 g, initially at rest, is acted upon by a variable force whose X-component varies with X in the manner shown. The velocities of the object at the points X = 8 m and X = 12 m, would have the respective values of (nearly)
Correct answer · Option 3
23 m/s and 24.4 m/s
Explanation
Work done equals change in kinetic energy: \( W = \frac{1}{2}mv^2 \). At \( X = 8\text{ m} \), area under \( F-X \) graph is \( \frac{1}{2} \times 4 \times 10 + (8-5) \times 10 = 20 + 30 = 50\text{ J} \). \( v_8 = \sqrt{\frac{2 \times 50}{0.5}} = \sqrt{200} \approx 14.14\text{ m/s} \).
