The velocity at point B after 2s is, v1=u+at1 v1=0+a(2) v1=2a The time t2 is, v2=v1−at2 0=2a−at2 t2=2s Total time of travel from A to C is, t=t1+t2 t=(2+2)s t=4s The distance between A and B is, AB=ut1+
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at12 AB=(0)(2)+
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a(2)2 AB=2a Thus, AB=BC=2a, and AC=4a When body return from C to A;u1=0 and Ac=4a The time taken to return from C to A is, AC=u1t′+
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at′2 4a=(0)t′+
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at′2 t′=2√2s Thus total time taken by body is, t0=t+t′ t0=(4+2√2)