physics grav fieldsWatch
and 17 (c) (ii) of this paper
For 17 (b) (ii) (3) , How did they get the y intercept as lg(GM) ?
and for 17 (c) (ii) , I got this equation: M(Earth) / M (Mars) = Radius of earth ^2 / Radius of mars ^2
but i dont know if this is correct
if anyone can help me out id be very grateful. Thanks
Try taking logs of both sides, you should come out with the y = mx + c form, with y being log(g) and x being log(r).
And looking at their answer for the other part, GM(Earth)/(re)^2 = GM(Mars)/(rm)^2, G cancels on both sides, and by multiplying by re ^2 and dividing by M(Mars) we get M(Earth) / M(Mars) = (re)^2/(rm)^2 which is what you got, so it is correct well done.