Question

A stone is dropped from the top of a tower and travels 24.5 m in the last second of its journey. What is the height of its tower ?

Answer 1

Distance travelled in nth second is
S = u + a(n - 0.5)

24.5 = 0 + 9.8(n - 0.5)
n = 2.5 + 0.5
n = 3

Distance travelled in 3rd second is 24.5 m

According to question 3rd second is last second. So time of fall is 3 seconds

H = 0.5gt²
= 0.5 × 9.8 × (3 s)²
= 44.1 m

Height of the building is 44.1 m