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A body travels a distance of 2 metre in 2 seconds and 2.8 metre in 4 seconds what will be the speed of the body at the end of the 10th second from the start |
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Answer» -1.7 m/s Explanation: USE equation of motion S = ut + 0.5at² In first 2 seconds 2 = 2u + 0.5a(2)² 2 = 2u + 2a 1 = u + a .....(1) In first 4 seconds 2.8 = 4u + 0.5a(4)² 2.8 = 4u + 8a 0.7 = u + 2a .....(2) Subtract (2) from (1) 1 - 0.7 = u + a - u - 2a 0.3 = -a a = -0.3 m/s² From equation (1) 1 = u + a 1 = u - 0.3 u = 1.3 m/s Speed at the END of 10th second v = u + at = 1.3 + (-0.3 × 10) = -1.7 m/s |
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