A speck of dust weighing 10−12 kg falls between the vertical plates of a flat condenser at the same distance from them. Due to the air resistance, the speed of a speck of dust is constant and equal to 1 mm/s. The capacitor is connected to a voltage source of 490 V, and after 10 seconds the speck of dust reaches one of the plates. Determine the charge of a speck of dust. The distance between the capacitor plates is 0.1 m. The resistance force is considered proportional to the speed of the dust mote.