A body dropped from the top of a tower covers a distance 7x in the last second of its journey where x is the distance covered in first second. How much time does it take to reach the ground (Take g=10 m/s2)?
The correct option is B 4 s
In first second, distance travelled x=12×g×t2=5 m
(for g=10 m/s2)
Distance travelled in last second =7x=35 m
We know that Sn=u+12a(2n−1)