Question

A stone is dropped from 25th storey of a multistoried building and it reaches the ground in 5s. In the first second it passes through how many storeys of the building?

$(g=10m/s^2)$

• A. 1
• B. 2
• C. 3
• D. None

Answer 1

The correct option is A

1

Suppose h be the height of each storey, then

$25h=0+\frac{1}{2}\times 10\times t^{2}h=5m$

Let the stone passes through n storey

$n\times 5=\frac{1}{2}\times 10\times (1{)}^{2}n=1$