On the surface of earth where is calculated by what

On the surface of the earth, weight is calculated by multiplying mass and gravity. Because we know the radius of the Earth, we can use the Law of Universal Gravitation to calculate the mass of the Earth in terms of the gravitational force on an object (its weight) at the Earth's surface, using the radius of the Earth as the distance.

I think this is the question you were trying to ask if not, ill try it again

a  solution  is always transparent, light passes through with no scattering from solute particles which are molecule in size. the  solution  is homogeneous and does not settle out. a colloid is intermediate between asolution  and a  suspension. while asuspension  will separate out a colloid will not.

3 1/4 %

explanation: