What is the force of a 12 kg rock falling at 9.8m/s/s

The ozone hole appears in antarctica during

Which changes would result in a decrease in the gravitational force btween two objects? check all that apply

Select all the correct answers. which changes will increase the rate of reaction during combustion? decreasing the area of contact between the reactants adding more oxygen to the reaction removing heat from the reaction changing the reactants from solid form to powdered form lowering the exposure of the reactants to air