Question

How much time does it take for the bill to fall beyond her grasp? the length of a bill is 16 cm?

Answer 1

Answer : t = 0.17 sec

Explanation :

It is given that :

length of a bill is,
`l=16\ cm=0.16\ m`

from second equation of motion:

`s=ut+(1)/(2)at^2`

Where u is the initial velocity

Here,
`u=0`

`s=(1)/(2)at^2`

`t=\sqrt{(2s)/(g)}`

`t=\sqrt{(2* 0.16\ m)/(9.8\ m/s^2)}`

`t=\sqrt{(0.3)/(9.8)}`

`t=0.17\ s`

0.17 s it will take for the bill to fall beyond her grasp

Answer 2

distance = 0.5 x g x t^2 where g is the gravitational force and t is the time required to cover the mentioned distance.

we have g = 9.8 m/sec^2 and distance = 16 cm = 0.16 m

From the above mentioned equation:
t = (2s / g)^0.5

Substituting with the givens, we can calculate t as follows:
t = [(2 x 0.16) / 9.8]^0.5 = 0.1807 seconds