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Physics · MOTION IN A STRAIGHT LINE
हिन्दीA car moving along a straight highway with a speed of \( 126\text{ km h}^{-1} \) is brought to a stop within a distance of \( 200\text{ m} \). Assuming constant deceleration, the magnitude of retardation and the time taken by the car to stop are respectively:
Correct answer · Option 4
\( 3.06\text{ m s}^{-2} \) and \( 11.4\text{ s} \)
Explanation
Speed \( u = 126 \times \frac{5}{18} = 35\text{ m/s} \). Using \( v^2 = u^2 + 2as \implies 0 = 35^2 + 2a(200) \implies a = -3.0625\text{ m/s}^2 \). Time \( t = \frac{0 - 35}{-3.0625} \approx 11.43\text{ s} \).
