The discussion revolves around the behavior of a negative charge placed at the origin, flanked by two positive charges of equal magnitude at equal distances. Participants explore the implications of this arrangement on the forces acting on the negative charge.
The conversation includes attempts to clarify the reasoning behind the net force being zero, with some participants suggesting the use of Coulomb's law and symmetry to understand the forces involved. There is an ongoing exploration of the implications of the forces without reaching a consensus on the broader context.
Some participants express uncertainty about the calculations involved and seek clarification on fundamental concepts related to electric forces and fields. The discussion reflects a mix of understanding and confusion regarding the application of Coulomb's law in this scenario.
If they are placed simultaneously,then the negative charge will stay still,because the net force is 0 and the initial state of the negative charge was "rest".negation said:A negative charge -q is placed at the origin.
Two positive charge of +4q are on both sides of the negative charge at distance d.
what happens?
adjacent said:If they are placed simultaneously,then the negative charge will stay still,because the net force is 0 and the initial state of the negative charge was "rest".
What do you think the net force is?negation said:Why is the net force = zero?
Doc Al said:What do you think the net force is?
negation said:I have no idea. Can you shed some light?
Use Coulomb's law to find the force that each positive charge exerts on the negative charge. But you should be able to use symmetry to figure out the net force on that center charge. No calculations needed.negation said:I have no idea. Can you shed some light?
Doc Al said:Use Coulomb's law to find the force that each positive charge exerts on the negative charge. But you should be able to use symmetry to figure out the net force on that center charge. No calculations needed.
Then you can consider the forces on the positive charges to see what happens to them.
Well, what's stopping you?negation said:Spot on. I'm looking for an interpretation without calculation.
I do know the calculation and the formula but in many cases, the question wants me to know what is happening without any empirical calculation.
Doc Al said:Well, what's stopping you?
How do the forces exerted by each positive charge compare?
Correct!negation said:Both positive charge exerts an outward electric field in a radial direction. The electric field from the positive charge to the left of the origin points in the positive x-direction. The electric field from the positive charge to the right of the origin point to the negative x-direction.
Since the negative charge is at an equal distance from both positive charge, the electric force experienced by the negative charge from the left is +F and -F from the right.
Fnet = -F+F=0?
Yes. Simple as that!negation said:Both positive charge exerts an outward electric field in a radial direction. The electric field from the positive charge to the left of the origin points in the positive x-direction. The electric field from the positive charge to the right of the origin point to the negative x-direction.
Since the negative charge is at an equal distance from both positive charge, the electric force experienced by the negative charge from the left is +F and -F from the right.
Fnet = -F+F=0?