Flashcards in Gravitational Fields Deck (18)
How is the force between two objects calculated?
F = (-G)M1M2/r^2
How is gravitational field strength calculated?
g = -GM/r^2
What is the unit of gravitational field strength?
How is gravitational field potential calculated?
How is gravitational potential energy calculated?
GPE = mVg = -GMm/r
What is the mass of the Earth?
6 x 10^24kg
What is the radius of the Earth?
What is the main property of the gravitational field lines around a spherical mass?
They are radial
What is the escape velocity of an object?
The minimum speed an object without propulsion needs to be able to escape from the gravitational field of a mass.
How is the gravitational force on a satellite calculated?
Fg = -GMem/r^2
How is centripetal force calculated?
Fc = -mv^2/r
How is the speed needed for a satellite to stay in orbit calculated?
v = √(GMe/re + h)
How is the time period of an orbit calculated?
T = 2πr/v
What is the relationship between time period and orbital radius?
T^2 ∝ r^3
How is the time period of an orbit calculated using the radius of the orbit?
T^2 = (4π^2/GMs)r^3
How is the gravitational potential at a point defined?
The work done in moving a 1kg mass from infinity to that point.
What is the total energy of a satellite?
GPE + KE = -GMems/2R