What is the difference between frictional and gravitational force?

Answer 1

Gravitational force attracts every massive particle to every other massive particle. It does so by altering the space between the objects, where each particle causes a small gravitational well. Frictional force is caused by the intermolecular attraction between two very close objects.

The main difference between these two forces is their dependence on distance between the objects. Gravitational force is inversely proportional to the square of the distance, classifying it as a long distance force. Conversely, frictional force depends mostly on London Dispersion/ forces, which has a magnitude that is inversely proportional to the distance to the sixth power. This is more clear in the equations modeling these two interactions:

FG=Gm1m2/r2 FL=k/r6

Where FG is the force of gravity and FL is the London force

G is the gravitational constant (6.674x10-11N(m/kg)2)

m1, m2 are the masses of the respective massive bodies

r is the distance between the respective bodies

k is a constant that depends on the polarizability and the ionization energies of the two bodies (in normal conditions other factors would have to be considered in this constant, but for an approximation this is sufficient).

Frictional force, unlike gravitational force, can be changed by the application of an external force perpendicular to the direction of the frictional force. Frictional force experienced by an object is equal to the product of the coefficient of friction (influenced by FL, shown above) and the normal force. Therefore, by changing the normal force (defined at the contact force perpendicular to the surface on contact, it keeps the object from falling through the surface) the frictional force can be changed. An intuitive example is moving a couch: the frictional force is much greater when there is someone sitting on it, increasing the normal force.

Answer 2

We all need energy to do work when we pull or push lift stertch or compress somethinhg a force is needed all the activites that we perform in our daily life involve force this force is exerted by the muscles of our body and is called muscular force

Answer 3

Its simple really. Friction is the force that slows things down due to the multiple particles hitting each other, even through the air.

While gravitational force is the force that bring object's with lower density or mass gravitationally locked to a object that has higher density or mass.

Answer 4

One is an acceleration, measured in distance/time^2

The other is a force, measured in mass x acceleration