- The document discusses Coulomb's law of electrostatics, which states that the force of attraction or repulsion between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. - It provides the units used to measure electric charge and gives the charge of an electron. - Coulomb's law can be used to calculate the net electrostatic force on an object from multiple charged spheres using their individual forces and distances.

1. COULOMB'S LAW ELECTROSTATICS

2. UNIT OF CHARGE x10 -12 pC PICO COULOMB x10 -9 nC NANO COULOMB x10 -6 μ C MICRO COULOMB x10 -3 mC MILLI COULOMB

3. + + + + + + + + + + + + + + + + - - - - - - - - - - - - - - - - - - - - CHARGE OF ELECTRON = - 1.6 X 10 -19 COULOMB CREATING CHARGE Charge created Charge of electron NUMBER OF ELECTRONS =

4. + + + + + + + + + + + + + + + + - - - - - - - - - - - - - - - - CHARGE OF EACH SPHERE = Q 1 + Q 2 2 TRANSFER OF CHARGE + + + + + + + + - - - - - - - - - - - - Charge transferred Charge of electron NUMBER OF ELECTRONS TRANSFERRED =

5. + - r Q 1 Q 2 COULOMB'S LAW F Q 1 Q 2 F F F r 2 1/r 2 k = 9 x 10 9 F = kQ 1 Q 2 r 2

6. WHAT HAPPENS WHEN VALUES CHANGE? + - r Q 1 Q 2 F + - 2xr 2xQ 1 F? BEFORE AFTER 2xQ 2 F= Q 1 Q 2 r 2 F= Q 1 Q 2 r 2 F= 2 x 2 2 2 F= 4 x 4 4 2 F= 1 F= 1

7. CALCULATE NET FORCE r Q 1 Q 2 Q 3 r F NET = F 1 ON 2 + (- F 3 ON 2 ) + - + F 1 ON 2 = kQ 1 Q 2 r 2 F 3 ON 2 = kQ 2 Q 3 r 2

8. MORE CALCULATIONS r Q 1 Q 2 F g = mg m m + + F 1 ON 2 = kQ 1 Q 2 r 2 kQ 1 Q 2 r 2 mg =