The gravitational force of attraction between two masses is inversely proportional to the square of the distance between them. Suppose that when a comet is 600 x 103 kms from the earth and receding at 12000 km/sec, the force between the comet and the earth is 3 kN. How fast is the force changing in kN/sec at that instant? a) -0.24 b) -0.18 c) -0.16 d) -0.12

106 MeV) is Extra: A very rare but occasionally observed decay of a muon µ (rest energy = into an electron e (rest energy 0.511 MeV) and a photon y (rest energy decays at rest by this mode, what is the kinetic energy of the electron and photon combined after the decay? (1M V = 10°eV = 1.6 x 10-13 J) zero). If a muon

Extra: You have two disks lying flat on ice, one has a string wrapped around the outside edge which unravels as you pull, the other has a string attached to a peg in the center. The discs have equal masses and dimensions and are initially at rest. If you start pulling both strings at the same time with the same constant force, at some time t later which of the two disks has moved further? Or have they both moved the same distance? Explain.

Find the acceleration due to Earth’s gravity at the distance of the Moon. if the distance between Earth and the Moon is 3.84*10^8 meters 1.04 and the Mass of the Earth is 5.98*10^24 Kg. a)  a= 9.81m/s^2 b) 2.70 *10^−3  c) 1.04 *10^6  d) 1.04 *10^5