The Hall affect is used to measure the carrier density of a thin sheet of electrons. When a current of 8.0 A flows through the 12-mm thickness electron sheet, a magnetic field of 0.75 T perpendicular to the sheet produces a voltage of 0.53 mV across the width of the sheet. What is the carrier density in the electron sheet?

You are traveling in a car going at a constant speed of 100km/h down a long, straight highway. you pass another car going in the same direction which is traveling at a constant speed of 80km/h. as measured from your car's reference frame this other car is traveling at −20km/h. what is the acceleration of your car as measured from the other car's reference frame? what is the acceleration of the other car as measured from your car's reference frame?