A bomb is falling vertically downwards into the air it explodes in air, then

A balloon of gross weight w newton is falling vertically downward with a constant acceleration a(lt g) . The magnitude of the air resistance is :

A balloon of weight w is falling vertically downward with a constant acceleration a(gt g) . The magnitude of the air resistance is

A balloon of gross weight w newton is falling vertically downward with a constant acceleration a(lt g) . The magnitude of the air resistance is :

A rain drop radius 0.3mm falling vertically downwards in air has a terminal velocity of 1(m)/(s) The viscosity of air is 18xx10^-5 poise. The viscous force on the drop is