Contrast the force of gravity between these pairs of objects a 1 kg mass and a 2 kg mass that are 1 m apart and two 2 kg masses that are 1 m apart

Solution

Force between pair of objects of masses 1kg and 2kg that are 1m apart is given as

here G is gravitational constant

G=

therefore,

similarly Force between pair of objects of masses 2kg each that are 1m apart is given as

or F'=2F

it means  Force between pair of objects of masses 2kg each that are 1m apart is equal to twice the Force between pair of objects of masses 1kg and 2kg that are 1m

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.