Theme D - D.1 - Gravitational Fields Flashcards
What is Kepler’s first law of orbital motion?
Each planet orbits the Sun along an elliptical path. The Sun is located at a focus of the elliptical orbit.
What is Kepler’s second law of orbital motion state?
The imaginary line joining the Sun and a planet sweeps equal areas of space in equal time intervals as planet follows its orbit.
What is Kepler’s third law?
The square of the orbital period of the planet is directly proportional to the cube of the average distance of the planet to the sun. T^2 ∝ r^3
What is Newtons universal law of gravitation?
Every object in the Universe attracts every other object with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distacne between their centres. The direction of the force is along th line joining the forces. F= G(Mm/r^2)
How do you find the orbital period?
Equate the gravitational force to the centripetal force.
What is a gravitational field?
Any region of space where a mass experiences a gravitational force.
What is gravitational field strength defined as?
gravitational force per unit mass g =F/m or g = GM/r^2
What is the formula for gravitational potential energy?
E = -G(Mm/r)
What is gravitational potential?
The work done per unit mass in bringing a small test charge from infinity to that point
What is the formula for gravitational potential?
V = -GM/r
Equipotential lines are always perpendicular to _ field lines.
gravitational
What is another formula for gravitational potential?
g = -(ΔV/Δr)
For small bodies how do we find the orbital energy?
Equate their kinetic energies.
How do you find the escape speed?
Equate kinetic energy to gravitational potential enegry
