A particle released from rest is falling through a thick fluid under gravity. The fluid exerts a resistive force on the particle proportional to the square of its speed. Which one of the following graphs best depicts the variation of its speed $v$ with time $t$ ?

Which of the following option correctly describes the variation of the speed $v$  and acceleration $'a'$  of a point mass falling vertically in a viscous medium that applies a force $F = -kv,$ where $'k'$  is a constant, on the body? (Graphs are schematic and not drawn to scale)

The average mass of rain drops is $3.0\times10^{-5}\, kg$ and their avarage terminal velocity is $9\, m/s$. Calculate the energy transferred by rain to each square metre of the surface at a place which receives $100\, cm$ of rain in a year

Which of the following graphs best represents the motion of a raindrop?

In an experiment, a small steel ball falls through a Iiquid at a constant speed of $10\, cm/s$. If the steel ball is pulled upward with a force equal to twice its effective weight, how fast will it move upward ? ......... $cm/s$

$1$ poiseille $=$ .......... poise