Gravitation test Errors
Q1. Prove Keppler's law , T2 = k R3. Answer = 1.87 yrs
Q2. g = GM/r2, using ratio of Venus and Earth , g = 9.88 ms-2
Q3. Draw g inversely proportional to r2 and potential inversely proportional to r. The relationship between g = - (gradient of potential -distance graph) .
b) F = GMm/r2, F/m = GM/r2, hence g = GM/r2.
Q4a) The orbit of the satellite passes through the centre of Earth and lie in the same Equatorial plane so that the two planes have the same axis of rotation . It can then be at the same point above the Earth.
b) Use 9.81 ms-2 to find Mass of Earth. Use M and substitute into equate GM/r2= w2r. r = 4.24 x 107m
c) The total energy of satellite = - GMm/2r = - 9.48 x 107J .
d) The negative sign implies that the satellite is bound to the Earth . It requires energy to escape from the gravitational field of Earth.
