- #1
Don Bones
- 6
- 1
I apologize ahead of time if this thread was made in the incorrect post. I have only taken Physics III (Mechanics) and am now taking Physics IV (Electricity/Magnetism). I have yet to find a description of every type of forum here.
In class, I was understanding everything that was mentioned and the professor decided to ask us if we understand. We all nodded and then he decided to mention to us that physics isn't as simple as it seems, and that we are only scratching the surface. Then he proceeded with the following situation.
Q: What happens when I have two positively charged objects next to one another?
A: The like charges repel. Sum of all forces are outward, away from one another.
Q: What happens when I push the two positively charged objects forward?
A: If they move fast enough, the like charges will attract to one another until the net force is directed between the two objects. This would be due to magnetic forces resulting from a current.
This was easy to understand after we looked at magnetic fields from wires of current, But then he asked another question that puzzled everybody.
Q: What happens if I have the charged objects near one another, hold them there with an external force, and then run away from the positively charged objects while observing them (external force removed as he runs and observes)? What does a bystander see if he stays still?
A: The charges now have velocity relative to the person running away. Because of this velocity, the positive charges become currents and the running man observes the charges attracting to one another. The bystander, however, observes the positive charges remaining where they are.
I am assuming this is just a "physics" thing rather than a realistic situation. Still I am confused and it would be nice if this was clarified.
In class, I was understanding everything that was mentioned and the professor decided to ask us if we understand. We all nodded and then he decided to mention to us that physics isn't as simple as it seems, and that we are only scratching the surface. Then he proceeded with the following situation.
Q: What happens when I have two positively charged objects next to one another?
A: The like charges repel. Sum of all forces are outward, away from one another.
Q: What happens when I push the two positively charged objects forward?
A: If they move fast enough, the like charges will attract to one another until the net force is directed between the two objects. This would be due to magnetic forces resulting from a current.
This was easy to understand after we looked at magnetic fields from wires of current, But then he asked another question that puzzled everybody.
Q: What happens if I have the charged objects near one another, hold them there with an external force, and then run away from the positively charged objects while observing them (external force removed as he runs and observes)? What does a bystander see if he stays still?
A: The charges now have velocity relative to the person running away. Because of this velocity, the positive charges become currents and the running man observes the charges attracting to one another. The bystander, however, observes the positive charges remaining where they are.
I am assuming this is just a "physics" thing rather than a realistic situation. Still I am confused and it would be nice if this was clarified.