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# A body travels for 15s starting from rest with constant acceleration. If it travels distances S1, S2 and S3 in the first five seconds, second five seconds and next five seconds respectively, the relation between S1, S2 and S3 is - (a) S1=S2=S3 (b) 5S1=3S2=S3 (c) S1=S2/3= S3/5 (d) S1=S2/5=S3/3

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## here the acceleration and the time interval in all three parts is the same part 1the body starts from rest with acceleration 'a' and attains a velocity 'v1' after t = 5 secondsso,s1 = 0 + (1/2)at2 (1)and v1 = 0 + atorv1 = at (2) part 2the body has an initial velocity v1 and accelerates to v2 after t = 5secondsso,s2 = v1t + (1/2)at2or from eq (2)s2 = at.t + (1/2)at2thus,s2 = (3/2)at2 (3)andv2 = v1 + atorv2 = at + at = 2at (4) part 3the body has an initial velocity 'v2' and accelerates to 'v3' after t = 5 secondsso,s3 = v2t + (1/2)at2or from equation (4)s3 = 2at.t + (1/2)at2sos3 = (5/2)at2 (5) now from equations (1), (3) and (5) we confirm thats1 = s2/3ands1 = s3/5ands2/s3 = 3/55s2 = 3s3ors2/3= s3/5thus, finally we gets1 = s2/3 = s3/5which is option (c)  Suggest Corrections  0      Similar questions  Related Videos   Equations of Motion
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