A positively charged oil droplet is descending through air in a uniform electric field directed vertically upwards. The droplet moves at a constant terminal speed $v_0$, and the electric field has strength $E$. The magnitude of the air resistance force on the droplet is proportional to the droplet’s speed. Which graph shows how $v_0$ varies with $E$?
Physics 9702 · AS & A Level · Momentum and Newton's laws of motion