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?
A) 3s
B) 4s
C) 5s
D) 6s
Correct Answer:
B
Solution :
Given, \[7x=\frac{g}{2}(2n-1)\] and \[x=\frac{1}{2}g{{(1)}^{2}}\] Solving these two equations \[n=4s.\]