HRW Chapter 21

Charge Sharing

Q2: How is charge distributed if these pairs touch?

(assume same size balls)

Henry Cavendish

Cavendish was silent and solitary, and was viewed as somewhat eccentric by many. He only spoke to his female servants by notes and formed no close personal relationships outside his family. By one account, Cavendish had a back staircase added to his house in order to avoid encountering his housekeeper because he was especially shy of women.

10 October 1731 – 24 February 1810Nice, France

Henry Cavendish*The concept of electric potential, which he called the "degree of electrification" *An early unit of capacitance, that of a sphere one inch in diameter *The formula for the capacitance of a plate capacitor *The concept of the dielectric constant of a material *The relationship between electric potential and current, now called Ohm's Law. (1781) *Laws for the division of current in parallel circuits, now attributed to Charles Wheatstone *Inverse square law of variation of electric force with distance, now called Coulomb's Law

10 October 1731 – 24 February 1810Nice, France

Charles-Augustin de Coulomb

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229 /109 CNmk

14 September 1736 – 23 August 1806 Paris

In 1781, he was stationed permanently at Paris. On the outbreak of the Revolution in 1789, he resigned his appointment as intendant des eaux et fontaines and retired to a small estate which he possessed at Blois. He was recalled to Paris for a time in order to take part in the new determination of weights and measures, which had been decreed by the Revolutionary government.

2212 /1085.8 NmCo

Joseph Priestly

13 March 1733 (Old Style) – 6 February 1804

English theologian, Dissenting clergyman, natural philosopher, educator, and political theorist

Q4: Where to place a 3rd charge so that Fnet =0 on it?

Q10: What is net force on the central charge?