Two small spheres of masses and are kept with their centres apart in air

PHYSICS · Subjective · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

Two small spheres of masses

5.0\,\text{kg}

and

12.0\,\text{kg}

are kept with their centres

20\,\text{cm}

apart in air. (i) Calculate the magnitude of the gravitational force between the spheres. (ii) The spheres are moved so that their centres are now

60\,\text{cm}

apart. Calculate the new force. (iii) Hence find the ratio of the second force to the first.