4.2 fields Flashcards
What is an electrical field?
Force per unit charge on a positive test charge placed in the field
What is the unit for electrical field?
NC^-1
What is Coulombs law?
The force between 2 charges is
-Directly proportional to the product of charges
-Inversely proportional to the square of their distance apart
-Maximum when charges are separated by a vacuum
What is Electric potential?
The work done per coulomb of positive charge in bringin the charge from infinity to the point
What is the unit for electrical potential?
JC^-1 or Volts
What are electrical equipotentials?
Surfaces that join up points if equal potential
-No work done if a charge is moved along an equipotential
-Always perpendicular to field lines
What is the potential gradient in a uniforn electric field?
The change in potential per meter at a point within an electrical field
What are the units of electric field strength?
JC^-1m^-1
Vm^_1
What is gravitational field strength?
The force experiencedx per unit mass by a mass placed in the field
What are the units of gravitational field strength?
-NKg^-1
What is Newton’s law of gravitation?
Every particle o matter attracts every other particle with a force that is
-Directly proportional to the product of their masses
-Inversely proportional to square of distance apart
What is gravitational potential?
The work done per Kg of mass to bring masss from infinity to that point
What is the unit of gravitational potential?
J Kg^-1
What is escape velocity?
The minimum velocity at which a projectile is thrown upwards to never return to Earth
