Question

a body falls from a large height H in t seconds the time taken to cover the last metre is​

Answer 1

a body falls from a large height H m in t second. we have to find the the time taken to cover the last metre.

time taken to cover last metre = time taken to cover H m - time taken to cover (H - 1)m

as initial velocity , u = 0

time taken to cover H m , t = √{2H/g}

so, time taken to cover (H - 1) m , t' = √{2(H -1)/g}

so, time taken to cover last metre = √{2H/g} - √{2(H - 1)/g}

= t - √{2(H - 1)/g} [ given, t = √{2H/g} ]

hence, time taken to cover last metre is t - √{2(H - 1)/g}