Question

pls answer in detail

Answer 1

hey bro may I know which book is it
actually this question was asked in tallentex 2017 class -9

time=n sec
acceleration=a
final velocity=v
initial velocity=u

so S in last sec
=u+a/2(2n-1)
=0+a/2(2n-1)
=a/2(2n-1)

so S in second last sec
=u+a/2(2(n-1)-1)
=0+a/2(2n-2-1)
=a/2(2n-3)

so on adding

a/2{2n-1+2n-3}
a/2{4n-4}
a(2n-2)

also v=u+at
v=an
a=v/n

on substituting
v/n(2n-2)
2v/n(n-1)

so (i) is correct

and ask where u didn't understand