calculate the force between two 5.0 kg spheres that are 2.5 m apart.
You must have been learning about Newton's universal law of gravity:
F = G*M1*M2/R^2
Use it. Looking up the value of G will be a worthwhile exercise.
F = G*M1*M2/R^2
Use it. Looking up the value of G will be a worthwhile exercise.