Question
Sat December 01, 2012 By:
 

A body falls 16m in the first second of its motion,48m in the next second,80m in the 3rd second and so on.How long will it take to fall 4096m?

Expert Reply
Sun December 02, 2012
the series for distance it fall is
16,48,80............... which is AP
let it takes N seconds to fall 4096m
therfor sum of series for N terms=4096
or (N/2)(2*16+(N-1)*32)=4096
or, 16(N^2)=4096
or, (N^2)=4096/16=256
or N=16
 
THerfor time required to fall 4096=16 seconds
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