AP EAMCET Engineering 21 Sep 2020 Shift 1 Paper

Since, stone falls freely, hence its initial velocity, u=0
Distance covered by the stone in first 5 s is given as
=122.5m
Since, distance travelled in last second (n th second) is equal to distance travelled in first 5s, hence
h1=u+‌

1

2

g(2n−1)
⇒‌‌122.5=0+‌

1

2

×9.8(2n−1)
⇒‌‌2n−1=‌

122.5×2

9.8

⇒‌‌2n−1=25
⇒‌‌2n=25+1
⇒‌‌2n=26⇒n=13