Question

A flower pot drops from the edge of the roof of a multistoried building .calculate the time taken by the pot to cross a particular distance AB of height 2.9 metre the upper point A being 19.6 m below the roof.

Answer 1

Answer:

0.14 seconds

Explanation:

u = 0 m/s

a = 9.8 m/s^2

s = 19.6m

v=?

v^2 - u^2 = 2as

=> v^2 = 2 x 9.8 x 19.6

=> v = 19.6 m/s

When the flower pot reaches point A,

u = 19.6 m/s

s ( AB) = 2.9 m

a = 9.8 m/s^2

v=?

v^2 - u^2 = 2as

=> v^2 = 2 x 9.8 x 2.9 + 19.6^2

=> v^2 = 56.84 + 384.16

=> v^2 = 441

=> v = 21 m/s

Now, we can find the time

t = ( v - u) /a

= ( 21 - 19.6)/9.8

= 0.14 s