Gravity: Chapter 6 Flashcards
Universal Law of Gravitation
There is a gravitational attraction between any two objects. Masses attract and the force acting on each mass is equal.
Inverse-square law
Force is inversely proportional to the square of the distance. The force of attraction drops quickly as two objects move apart.
Gravitational field
A collection of vectors, one at each point in space, that determines the magnitude and direction of the gravitational force.
Gravitational field strength
The magnitude of the gravitational field vector at a point in space.
Satellite
An object or body that revolves around another body due to gravitational attraction.
Artificial satellite
An object that has been intentionally placed by humans into orbit around earth or another body; referred to as “artificial” to distinguish from natural satellites such as the moon.
Orbital radius
The distance between the venture of the satellite and the centre of its parent body.
What is the formula for finding the orbital radius
V = √GM/r2
Geosynchronous orbit
The orbit around earth of an object with an orbital speed matching the rate of earths rotation; the period of such an orbit is exactly one earth day. V = 2πr/t.
Law of Electric Charges
Like charges repel and unlike charge attract.
How do you calculate the total charge of an object?
Calculate the sums of the charges.
A deficit of electrons
Means object is positively charged
Excess of electrons
Number is negatively charged.
Law of conservation of charge
In the transfer of any charge from one object to another, charge can be created or destroyed, but the total charge of a closed system remains constant.
Coulomb?
The SI unit for charge.
When does electric force become stronger?
As the amount of charge is increased.
Electric force
A force with magnitude and direction that acts between two charged particles.
Coulomb’s law
The force between two point charges is inversely proportional to the square of the distance between charges and directly proportional to the product of the charges.
What is a similarity between Coulomb’s law and universal gravitation?
Both of these laws describe the force between two objects on both depend on certain properties of the object involved. Both laws state that the gravitational force and electric force decrease as the distance between the two interacting objects increases.
Electric field
The region in which a force is exerted on an electric charge; the electric force per unit positive charge; unit is N/C. Denoted by E.
electric field lines
The continuous lines of force around charges that show the direction of the electric force at all points in the electric field.
Electric dipole
A pair of equal and opposite electric charges with centres separated by a small distance. Field lines from -q and +q alone are just field lines going inward and outward, but when they are put farther apart it causes the field lines to bend they interact with each other creating a net electric field.
When is the electric field uniform
When the planes of charge extends from the positive plane of charge to the negative plane and is uniform.
Is work equal to electric energy?
Yes
