In: Physics
A planet of mass 6 × 1025 kg is in a circular orbit
of radius 4 × 1011 m around a star. The star exerts a
force on the planet of constant magnitude 1.8 × 1023 N.
The speed of the planet is 3.4 × 104 m/s.
(a) In half a "year" the planet goes half way
around the star. What is the distance that the planet travels along
the semicircle?
(b) During this half "year", how much work is done on the planet by the gravitational force acting on the planet?
(c) What is the change in kinetic energy of the planet?
(d) What is the magnitude of the change of momentum of the planet?