Azinc atom has 30 electrons. to what level are it's electrons found

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?

Find v(t), given acceleration a(t)=7j and initial velocity v(0)=k

Explain why electric current cannot exist if a current doesn't have a voltage source.