Question

Choose two forces and compare and contrast these forces. These must be different forces than used in the prior question. Provide two ways that they are similar and two ways that they are different. You may make a list, write it out, or make a chart.

Answer 1

Let us consider two forces as Coulombic electrostatic force and gravitational force.

Coulombic electrostatic force : Let us consider two charges q and q' separated by a distance r in a medium having electric permittivity
`\epsilon`. Hence the electrostatic force is given as -

`F=(1)/(4\pi\epsilon) (qq')/(r^2)`

Gravitational force : Let us consider two bodies having mass m and m' separated by a distance r in any medium. The gravitational force between them is given as -

`F= G(mm')/(r^2)` where G is the universal gravitational constant.

Now we have to show the similarities between two forces:

1- The two forces are conservative in nature i.e the work done by them is independent of path followed and work done in a closed path is zero.

2- The two forces obey inverse square law.

3-The two forces are central force. They act along the line joining the centres of two bodies.

Now we have to show the dissimilarities between them:

1- The Coulombic force may be attractive or repulsive depending on the nature of charges while gravitational force is always attractive in nature.

2-The Coulombic force is dependent on the medium where as gravitational force is independent of medium