In an experiment, a small steel ball falls through a liquid 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?

Weight of the body W=mg=43πr3ρgT=43πr3σg and F=6πηvr When the body attains terminal velocity net force acting  on the body is zero. i.e., W−T−F=0 And terminal velocity v=29r2(ρ−σ)gη As in case of upward motion upward force is twice its  effective weight, therefore, it will move with same speed 10 cm/s.