rods and pivot With one charged rod on a pivot, use another of the same or opposite charge to show attraction or repulsion. Show attraction or repulsion with rods on a pivot or hung by a thread. Located in Electrostatics Cabinet, A1
Rub clear rod with cat fur. Clear rod charges positive. Place it in stirrup (which hangs from non-conducting silk thread) as shown.
Rub black rod with cat fur. Black rod charges negative.
Hold black rod near clear rod. The two rods attract.
Rub second clear rod with cat fur. Second clear rod charges positive. Bring second clear rod near first clear rod. The two rods repel. Thus there are two kinds of electric charge.