Question

What is the difference between a contact force and a field force?

A contact force requires two objects to be touching, a field force works at a distance
A contact force requires two objects to be touching, a field force requires a magnetic field to work
A contact force works at a distance, a field force requires objects to be close to each other
There is no difference between contact and field force

Answer 1

A contact force requires two objects to be touching, a field force works at a distance

Step-by-step explanation:

- A contact force is a force that requires the two objects to be touching. An example of contact force is the frictional force: in fact, frictional force only occurs if the surfaces of the two objects involved touch each other, otherwise it is not present.

- A field force is a force that acts on a distance, i.e. the objects involved do not need to touch. Examples of field force are the gravitational force and the electric force: in fact, an object with mass
`m` experiences a force of gravity when it is near a planet, but this force is present also when the object is not touching the planet. Similarly, electric charges experience an electric force when they are close to other electri charges, even when they are separated by a certain distance r. For this non-contact forces, we use the concept of field to identify the region of space in which an object experiences that force.