- #36
hefalomp
- 14
- 1
I think i figured it out, i used wrong radius, i forgot to add up the radius of the Earth as well :s, i now got 6170 s, is that the same as u got?Makonia said:
I think i figured it out, i used wrong radius, i forgot to add up the radius of the Earth as well :s, i now got 6170 s, is that the same as u got?Makonia said:No I got 6000 and something s, your formula looks wrong so you should try to do it again
No, I got a little bit more. You used this equation: T = 2*pi*r / (sqrt(G*M/r)?hefalomp said:I think i figured it out, i used wrong radius, i forgot to add up the radius of the Earth as well :s, i now got 6170 s, is that the same as u got?
I guess we have just done it differently. I got the formula: T=sqrt((4*pi^2*r^3)/(G*M))hefalomp said:Yes, might be that that is wrong then? But you said that (G*M*m)/r^2 is the force and since F=m*a where a=v^2/r you can solve the problem by solving it for v and then setting in the formula for T instead. Can i not use that (G*M*m)/r^2 = m* v^2/r, and solv it for v, then put v in T = 2*pi*r/v ?
Even when I use your formula i also get 6170 seconds, do you use r = 7271000 , M = 5,97219*10^24 and G = 6.67408*10^-11 ?Makonia said:I guess we have just done it differently. I got the formula: T=sqrt((4*pi^2*r^3)/(G*M))
No I use the values for r, M and g stated in the task. In other words M=6*10^24, r = 7300*10^3 and I used G with two decimalshefalomp said:Even when I use your formula i also get 6170 seconds, do you use r = 7271000 , M = 5,97219*10^24 and G = 6.67408*10^-11 ?
Well, that's explanes why i got wrong, i searched for the radius and mass of Earth on google, didnt se that they were mentioned in the task :) Now i should get the right answear..Makonia said:No I use the values for r, M and g stated in the task. In other words M=6*10^24, r = 7300*10^3 and I used G with two decimals