If you comb your hair, for example, electrons leave the atoms and molecules in your hair and travel to the plastic comb. The comb, covered in negatively charged electrons, becomes negatively charged as well, and your hair is left with a positive charge.
If two objects have different charges, they attract or pull towards each other. If two objects have the same charge, they repel or push away from each other. Since things with the same charge repel each other, the hairs try to move away from each other by standing up and away from all the other hairs, resulting in you having a very funny-looking hairdo!
Another example: if you walk across a carpet, electrons move from the rug to you. Now you have extra electrons. If you have extra electrons piled on you, they will spill off when you touch an object like a doorknob, and give you a shock. Shocks come from gaining or losing electric charge in a hurry. When a charged object is brought close to a neutral material, the electrons on the neutral material will either move toward the charged object if it has a positive charge or away from the charged object if it has a negative charge.
This phenomenon is called an induced charge. The result is that a normally neutral material will have a slight charge when near the charged object, and it is enough for the two to attract. Electrostatic charges are not caused by friction, although many assume this to be the case. Rubbing a balloon on your head or dragging your feet on the carpet will build up a charge, but so will ordinary walking or repeatedly touching your head with a balloon!
With this in mind:. The three diagrams above are examples of electric fields. The lines in the diagrams are lines of force. These show how charged particles will move in the electric field.
The direction of the arrow shows the direction in which a positively charged particle will move. The spacing between the field lines gives an indication of the strength of the force. If the lines are close together the force will be greater, eg close to a charged particle in a radial field. A charged object will experience non-contact force from another charged object. The type of force will depend on the type of charge positive or negative on the two objects. The properties of attraction and repulsion are often used to show that an object is charged:.
If a negatively charged plastic rod is brought near to another negatively charged rod, they will move apart as they repel each other. If a positively charged rod is brought close to a negatively charged rod, they will pull together as they attract each other. The forces of attraction or repulsion are greater when the charged objects are closer.
If a cloth rubs a plastic rod and the cloth is pulled away from the rod slightly, will the rod and cloth attract, repel or experience no force at all?
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