Presentation on theme: "Van de Graaff Generator Robert J. Van de Graaff Q1) How does it work? Q2) How does a Leyden jar store charge? Q3) How does a dead rabbit come back to."— Presentation transcript:
Van de Graaff Generator Robert J. Van de Graaff Q1) How does it work? Q2) How does a Leyden jar store charge? Q3) How does a dead rabbit come back to life?
If a hydrogen atom was the size of Metlife Stadium, how big would the nucleus be?
Detecting Charge: Charge Detecting Devices Describe Rutherford's findings in his famous Gold Foil Experiment. RULES
3 Methods of Charging Separation of Charge Charging by Conduction Friction (CONTACT) Friction (CONTACT) Outcome Outcome Outcome Induction by Grounding (NO CONTACT) (NO CONTACT)
Q1) How does it work? Q2) How does a Leyden jar store charge? Q3) How does a dead rabbit come back to life?
A Leyden jar, is a device that "stores" static electricity between two electrodes. It was the original form of a capacitor (originally the original form of a capacitor (originally known as a "condenser"). It was invented by German cleric Ewald Georg von Kleist on 11 October 1745 and by Dutch scientist Pieter van Musschenbroek of Leiden (Leyden) in 1745–1746. The invention was named for the city. The Leyden jar was used to conduct many early experiments in electricity, and its discovery was of fundamental importance in the study of electricity. A famous use of the Leyden jar was Benjamin Franklin's kite experiment, which gave rise to the phrase "capture lightning in a bottle".
Units of Charge: Negative ChargePositive Charge Negative Charge Positive Charge Elementary Particles (e) => Coulombs (C) Elementary Particles (e) => Coulombs (C) What is the charge in Coulombs for... a) -6e a) -6e b) +3e b) +3e Coulombs (C) => Elementary Particles (e) Coulombs (C) => Elementary Particles (e) How many extra/fewer e - does object have with charge of... a) -3.2 X C a) -3.2 X C b) 2.0 X C b) 2.0 X C ELECTRON CANNOT BE CUT INTO PIECES!!
Conservation of Charge & Charge Transfer: 2 metal spheres touch then separate… Total Charge = AB AB BEFORE AFTER a)What is the charge on each sphere after contact? b)What subatomic particle(s) were transferred? From where to where? c) How much charge did A gain in elementary particles and Coulombs? d)How much charge did B lose in elementary particles and Coulombs? What if?
MicroCoulomb (μC) : a) How many elementary particles? b) How many MicroCoulombs? -5 μC 3 x e -5 μC 3 x e Analogy: 325cents. How many Quarters? Analogy: 636eggs. How many dozen? Multistep Charge Transfer Net Charge = q 0 0 Net Charge = Two spheres have charges of +3µC and +7µC respectively... a)What is the charge on each sphere after contact? b)How much charge was transferred in.. i) µC ii) C iii) e Δq=
Coulombs Law: Two 1kg charged objects with charges of +2C and -4C are.5m apart… a)What is the electrostatic force (F e ) between the objects? b)What would be force if charges were +2C and +4C? c)What is the gravitational force (F g ) between the objects? Inverse Square LawRelationships a) 4r b) 2q 1 c) 2q 1, 3q 2 d) 3q 1, 3q 2, 3r FeFe FeFe FeFe FeFe
In the Bohr model of the hydrogen atom, an electron orbits in the ground state at a radius of 5.29x m… a)What is the electrostatic force that holds the electron is orbit? b)What is the velocity of the electron? c)What is the period of an electrons orbit? d)What is the force of gravity between the proton and the electron?
DO NOW: Two protons are separated by 1 x m… a)Draw and label the Fg and Fe vectors on each proton… b)Calculate the Fg and Fe… c)What is Fnet on each proton? What will be the acceleration? d)How far apart are the two protons if Fe = 5.75 x N?
Electric Field -E-Field Intensity/Strength Electric Field Lines Direction:Rules: E-Field vs. G-Field a)What is the electric field strength if a point charge of 2C feels an attractive force of 10N? b)Given the field strength in part ‘a’, how much force would a proton feels in this field? c)If the sphere and the point charge are.1m apart, what must be the charge on the sphere?
Do NOW: A +1C point charge finds itself in an E-Field with a strength of 250N/C. If the point charge has of charge on it.. a) How much force does it feel? b) If the point charge is.5m away from source of E-Field, how much charge is present at the source of the E-Field? Complete the Graphs Fe Fe Fe E E qr r