Question

An arm-wrestling competition among a strong person and a weak person is an example of ________.
A) balanced forces
B) unbalanced forces
C) net force
D) frictional force

Answer 1

An arm-wrestling competition is a show of strength between two people. The stronger person is more likely to exert more force than the weaker person and so the hand of the weaker contestant can be observed to displace and touch the surface.

Complete step by step answer.
Step 1: Describe the nature of the force involved in the arm-wrestling competition between the strong person and the weak person.
The force exerted by a person depends on the mass of his or her body.

It is a common conception that the stronger person has a more massive body. Let us too follow this conception. If so then the stronger person will indeed apply more force on his hands to beat his weaker opponent. The weaker opponent being less massive will apply a lesser force. So the two forces in play do not share the same magnitude and thus are described as unbalanced forces.

Hence the correct option is B.

Additional information: Net force refers to the total force acting on a system. Frictional force arises when an object comes in contact with a rough surface or another object, opposing the motion of the object. Here as the elbows of the contestants are in contact with a horizontal surface, frictional forces are likely to arise between their elbows and the surface. But they are background forces in the given scenario.

Note: Here the direction of the resultant force of the two forces applied by the two contestants will be along the direction of the greater force. So it will allow the stronger contestant to force his weaker opponent’s outer palm to make contact with the surface. When balanced forces act on a system the net force will be zero and no displacement will be observed as the two forces trying to cause displacement cancel each other out.