1: INTERACTIONS OF ELECTRIC CHARGES Suspend a U tape from a thread or a hair. Hold the thread or hair in your hand, or use a short piece of tape to stick the upper end of the thread or hair to the desk. Approach the suspended tape from various directions with another U tape. Do you find that the force does indeed act along a line drawn from one object to the oth Force along line connecting the two charged objects? F? Hanging from thread or hair Flosed act along a line 1.2.4 Two U tapes: Effect of distance 1.2.3a Move a U tape very slowly toward a hanging U tape. Observe the deflection of the hanging tape from its original position, at several distances (for example, the distance at which you first see repulsion, half that distance, etc.) Make a very rough graph of the strength of the repulsive interaction as a function of the distance between the two tapes (you can't really go all the way to 0 distance!). The deflection of the tape away from its original vertical position is a measure of the strength of the interaction. Deflection from original position (measure of U-U repulsion) 0 0 Distance between the two tapes 1.2.4a Note: The real world is messy You may have noted several difficulties in making accurate measurements of displacement versus distance. For example, the tapes are both attracted to your hand, as well as repelling each other. If you tried to use a ruler, you may have found that the tapes are attracted to the ruler, too. For now, we'll settle for rough observations, but keep these difficulties in mind.