Two small spheres experience a gravitational force of when their centres are apart

PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

Two small spheres experience a gravitational force of

60\,\text{N}

when their centres are

0.50\,\text{m}

apart. At what separation will the force become

15\,\text{N}

, all other factors remaining unchanged? (a)

2.0\,\text{m}

(b)

0.25\,\text{m}

(c)

1.0\,\text{m}

(d)

0.71\,\text{m}