The force the attraction between two magnets is F Newtons. This force is inversely
proportional to the square of the distance, d centimetres, between the magnets.
(a) When the magnets are a certain distance apart, the force is 10 Newtons.
What is the force when the distance is doubled ?
(b) (i) Write down a formula connecting F,d and a constant k.
(ii) When the magnets are 3 cm apart, the force is 2 Newtons.
Find the force when they are 5 cm apart.
