QUESTION: a small dust mote of mass [tex]3.2x10^-12[/tex]kg is between two metal plates (one + one -)which can be conected to a 20V power supply. When the power supply is turned on, an electric field of 400 V/m is established. It is observed that the mote starts from rest when the field is turned on (t=0) and travels 1.0 mm in 10s. a) what is the charge on the mote? b) the mote moves toward the positive plate, what is the sign of the charge? c) what is the direction of the electric field between the plates? Alright... I have a really hard time with these questions, and frankly dont know where to start or how to tackle this. Can someone please help me out with this?