Question

A stone is dropped from the top of a tower and travel 24.5 m in the last second of its journey the height of the tower is

Answer 1

Distance traveled in nth second =

u + a/2(2t-1)

Here,

24.5 = u + a/2(2t-1). [t is the time taken][u is the initial velocity = 0] [a=9.8]

24.5 = 4.9(2t-1)

24.5 = 9.8t - 4.9

29.4 = 9.8t

t = 3 sec

This means,

stone reaches the ground in 3 seconds

Now

h= ut+0.5at² [u=0;a=9.8;t=3]

h= 0.5x9.8x3²

h= 4.9x9

h=44.1m

Hope this helps