10th
10. A motorist is travelling at 54 km/hr when he observes a traffic signal at a distance of 280 m ahead turning red at time t = 0. If he decides to decelerate & then accelerate by the same magnitude, so as to pass the signal at 54 km/he at t = 28 seconds, when the signal turns green, then
(A) Magnitude of deceleration is 5 7 m/s2                 (B) Magnitude of deceleration is 1 m/s2
(C) Minimum speed reached is 5 m/s                       (D) Minimum speed reached is 10 m/s

Dear student,u=54km/hr=15m/sS=ut+12at2280=15×28+12×a×28×28a=-0.35m/sv=u+atv=15+(-0.35)×28v=5.2m/s5m/sSo option C is correctRegards

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