It is a common observation that rain clouds can be at about 1 km altitude above the ground. If a rain drop falls from such a height freely under gravity, then what will be its speed in km ? (Take g = 10 m )

Question

It is a common observation that rain clouds can be at about 1 km altitude above the ground. If a rain drop falls from such a height freely under gravity, then what will be its speed in km $h^{- 1}$ ? (Take g = 10 m $s^{- 2}$ )

Smart Achievers · Accepted Answer

(1)

$Here, u = 0, g = 10 m s^{- 2}, h = 1 km = 1000 m$

$As$ $v^{2} - u^{2} = 2 g h$ $∴$ $v^{2} = 2 g h$

or $v = \sqrt{2 g h} = \sqrt{2 \times 10 \times 1000} = 100 \sqrt{2} m s^{- 1}$ $↓ + v e$

$= 100 \sqrt{2} \times \frac{18}{5} km h^{- 1} = 360 \sqrt{2} km h^{- 1} \approx 510 km h^{- 1}$

Solution

Q.
It is a common observation that rain clouds can be at about 1 km altitude above the ground. If a rain drop falls from such a height freely under gravity, then what will be its speed in km $h^{- 1}$ (Take g = 10 m $s^{- 2}$ )

1 510

2 610

3 710

4 910

Want Us to Email you About Special Offers & Updates?