Why can you hear a man's voice around the corner of a building even if you can't see him? OA. Interference

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?

Which subatomic particle has a negative charge

Find the magnetic field a distance r from the center of a long wire that has radius a and carries a uniform current per unit area j in the positive z direction.