Use these values in your computations, and don't round off!
    Radius of Earth         Re    =    6.37 x 10^(6)     m
    Mass of Earth           Me    =    5.98 x 10^(24)    kg
    Mass of bullet          m     =    1.00              kg
    Grav constant           G     =    6.67 x 10^(-11)   N*m^2/kg^2
    R1               R2             gained GPE (J)    initial speed (m/s)
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1 Earth radius      2 Earth radii                                       
1                  11
1                 101
1               1,001
1              10,001
1             100,001
1           1,000,001
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