Gravitation Flashcards
Define Newtons law of gravitation
A force of attraction due to gravity exists between any two objects and that the force of gravity between two objects is proportional to the product of the masses of the objects and inversely proportional to the square of their distance apart
What is the nature of a force when it is attractive
Negative
Describe point mass systems
Field lines pointing towards to the object
Arrows get bigger closer you are to the object
Describe field lines with 2 bodies
Attractive to each object
Field lines for each object repel each other
Denser they are closer to the object
Greater the object the greater the field
Describe field lines close to the earths surface
Field lines are parallel to one another and arrive perpendicular to the surface
Plotting gravitational field strength
Straight line from origin to g along radius
After radius, exponential decrease of g
How do we calculate combined gravitational field strength
g1+g2 as they are vectors, g1 is the “positive” field strength
What do all potential energies have incommon
W=Fd is the same equation for both
What are conservative forces
Forces which are responsible for potential energies
What is the relationship between work done and potential energy
As work increases, potential energy decreases
What happens to the gravitational potential energy of an object as it travels further away from a stationary gravitational body
GPE increases
What is gravitational potential
Gravitational potential energy per unit mass
How to calculate field strength at a particular value of r on a graph
Negative gradient of the gravitational potential at that point
Define escape velocity and how to calculate it
Minimum speed required to overcome the gravitational potential energy of the rocket in Earth’s gravitational field
Equate kinetic energy to force between two masses and rearrange
Define Equipotnetial surfaces
Surfaces where the gravitational potential does not change
