Electricity & Megnetism

# coulomb’s and newton’s gravitational law: differences and similarities

## Comparison of Coulomb’s law and Newton’s law of gravitation

The electrical force between two charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them:It is expressed

The gravitational force between two masses is directly proportional to the product of their masses and inversely proportional to the square of the distance between them:

### Similarities among the electrical and Gravitation force

- Both forces are the conservative forces.
- Both forces obey the inverse square law.
- The charge ‘q’ plays the same role in the coulomb’s law that the mass ‘m’ plays in newton’s law law of gravitation.

### Differences among the electrical and gravitational force

- Electrical force is might be attractive as well as repulsive,while the gravitational force is only attractive.
- Electrostatic force is medium dependent and can be shielded while the gravitational force lacks this property.
- The value of gravitational constant is very small while the electrical constant is very large.It is because of the fact that gravitational force is very weak as compared to electrical force.
- In using the law of gravitation,we define mass ‘m’ from F=ma ,then determine ‘G’ by applying gravitational law to known masses.While in case of coulomb’s law,we define ‘k’ for particular value and then determine ‘q’ by applying coulomb’s law.