Question

Rain drops are falling with a constant speed by the time they reach the ground because.

• A. Rain drops originate in outer space where the gravitational forces are negligible
• B. The force due to air resistance increases with the speed of the rain drops until it balances the gravitational force
• C. Rain drops are two light and hence not affected by acceleration due to gravity
• D. The force due to air resistance is constant and balances the gravitational force

Answer 1

The correct option is B The force due to air resistance increases with the speed of the rain drops until it balances the gravitational force

The force acting on a rain drop which falling down are its weight $w=mg$ and Air resistance $R=k{v}^2$

Net force $=W-R=ma$

Here $W=$constant , $a=$acceleration , $R=$ Variable

$R$ is increasing with speed of drop and net acceleration to decrease .

When $R=W$(at one stage )

net force on the rain drop is zero $(a=0)$. And after that forces.Due to air resistance increases with the speed of the rain until it balances the gravitational force.