Gravitation See video on extreme sports --- defying gravity See video on Gravitation
Newton’s Law of Gravitation Any two point masses attract each other with a force that is proportional to each of their masses and inversely proportional to the square of the distance between them.
average distance from the Earth to the Sun = 1.5 1011 m. Data G = 6.67 10-11 N m2 kg-2 mass of the Earth = 6.0 1024 kg radius of the Earth = 6.4 106 m mass of the Sun = 2.0 1030 kg average distance from the Earth to the Sun = 1.5 1011 m.
Questions Page 123 Bath Advanced Science Physics
Gravitational Field Field lines never start or stop at empty space Field lines never cross Gravitational field strength at a point is the force per unit mass exerted on a mass placed at that point.
Questions Page 126 Bath Advanced Science Physics
Work Energy Gravitational Potential Energy Gravitational potential energy is energy an object possesses because of its position in a gravitational field
Potential The potential at a point in a field as the gravitational potential energy per unit mass placed at that point in the field Equipotentials join points of equal potential
Questions Page 128 Bath Advanced Science Physics
Kepler’s Laws (see video) All of the planets move in elliptical orbits with the Sun at one focus.
Kepler’s Laws (see video) The radius vector (imaginary line between the Sun and the planet) sweeps out equal areas in equal times.