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# Help with the gravitation question please watch

1. Help with the gravitation question please

2. The gravitational field strength is proportional to the product of density and radius. Does this help?

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This is because and and
3. (Original post by Mr M)
The gravitational field strength is proportional to the product of density and radius. Does this help?

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This is because and and
thanks that was a bit helpful
4. (Original post by Beamchain)
thanks that was a bit helpful
Just a bit?!
5. 1st calculate the volume (1.6x10^7)^3 x 4pi/3 = 1.715x10^22
now times by 3000 to get mass = 5.14x10^24
g=((6.67x10^-11)x(5.14x10^24))/((1.6x10^7)^2) = 13.4N/kg
6. (Original post by shahbaz)
1st calculate the volume (1.6x10^7)^3 x 4pi/3 = 1.715x10^22
now times by 3000 to get mass = 5.14x10^24
g=((6.67x10^-11)x(5.14x10^24))/((1.6x10^7)^2) = 13.4N/kg
It isn't necessary to make any calculations to obtain the correct answer.
7. (Original post by Mr M)
It isn't necessary to make any calculations to obtain the correct answer.
Why not?
8. (Original post by shahbaz)
Why not?
Because the product of density and radius is the same for both planets.

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