A student made the table shown to list some contact and non-contact forces. Examples of Forces
Contact Forces Non-Contact Forces
The upward force applied by a couch on a student sitting on it The force applied by an electromagnet on a wire
The force applied by a student on a box to move it The force which opposes the motion of an object on a rough surface

Which statement best explains why the table is incorrect?
Normal force is a force acting at a distance.
The student applies a non-contact force on the box.
The electromagnet and wire have to be in contact to apply the force.
Frictional force acts between the object and the rough surface when they are in contact.