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A man travelled 200m in 4 second 220m in 2 second then find velocity at 7th second |
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Answer» List the main difference between mitosis and meiosis 1Q, summary of sweetest love I,Do Note Goe Let \'u\' be the initial velocity and \'a\' the acceleration.So we have the distance formulas = ut + 1/2 at^2In first 2 seconds,s = 200Put the values in the formula.200 = u x 2 + 1/2 x a x (2)^2200 = 2u + 1/2 x 4 x a200 = 2u + 2a100 = u + a -----(I)In next 4 secondsLet the distance traveled be \'y\'Time = 2+4 = 6 secSo according to the formula ,y = u x 6 + 1/2a x (6)^2y = 6u + 1/2 x 36 x ay = 6u + 18a ------(ii)Now we know that 220 cm was traveled in between 2 sec - 6 secy - 200 = 220y = 420We know y = 6u + 18a (from [ii])So, 6u + 18a = 420u + 3a = 70 ------(iii)Equating (I) and (iii)-2a = 30a = -15 cm/s^2u = 100 - (-15)u = 100 + 15 = 115 cm/secNow we know v = u + atWe have to find the "v" after 7th secondSo v = 115 + (-15) x 7v = 115 - 105v = 10 cm/sec |
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