Question

What are 2 examples of external forces? How do you know they are external forces?

a) Gravitational force and electromagnetic force, identified by their origin outside the system.
b) Tension in a rope and frictional force, known to act from an external source.
c) Normal force and air resistance, determined by their action on an object from outside.
d) Inertia and weight, recognized as forces acting on an object from an external environment.

Answer 1

Gravitational force and electromagnetic force are examples of external forces that act from outside the system.

Step-by-step explanation:

An external force is a force acting on an object or system that originates outside of the object or system. Based on this definition, two examples of external forces are the gravitational force and the electromagnetic force. These forces are considered external because they originate from outside the system of interest. For example, the gravitational force is exerted on objects by the Earth, which is external to the objects being affected. Similarly, the electromagnetic force, such as the force between two charged particles, also acts from outside the system.