How does the force of gravity change as the distance between 2 objects change ?

If a textbook weighs 37.2 n on venus, and the book has a mass of 4.4 kg, what is the strength of gravity on venus? 8.9 m/s28.9 m/si don't have enough information,9.8 m/s2

Carbon is allowed to diffuse through a steel plate 15 mm thick. the concentrations of carbon at the two faces are 0.65 and 0.30 kg c/m^3 fe, which are maintained constant. if the preexponential and activation energy are 6.2 x 10-7 m2 /s and 80,000 j/mol, respectively, compute the temperature at which the diffusion flux is 1.43 x 10^-9 kg/m^2 -s.

The earth exerts a gravitational force of 500 n on amy. what is amy’s mass in kg?