Two objects of equal mass are a fixed distance apart. if the mass of each object could be tripled, the gravitational force between the objects

gravitational force between two objects is given as

F = G m₁ m₂/r²

where m₁ = mass of first object , m₂ = mass of second object , r = distance between the two objects .

Initial case :

m₁ = m₂ = m

gravitational force between the objects is given as

F = G m²/r²

Final Case :

m₁ = m₂ = 3 m

new gravitational force between the objects is given as

F' = G (3m)²/r²

F' = 9 G m²/r²

F' = 9 F

hence the gravitational force between the two objects becomes 9 times.

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.