Force always acts pairs from "summary" of Newton's Laws of Motion by Edward Shevick

Force is operational in both directions. For example, when one object pushes against another object, the second object will also push against the first. This means that for every action there is an equal reaction.

It isn't just objects which are affected by force operating in pairs. Events which we experience can also fall into this category. The more effort you put into something, the greater the impact or consequences could be.

We often talk aboutforces being balanced. When two opposite forces act on an item they balance each other out to create equilibrium. Without the opposing force, the original force would cause movement or change.

Forces always come in two parts; a push and a pull. Whenever something moves, it experiences these forces pushing and pulling, so action and reaction always occur simultaneously and with equal intensity.

In physics, the principle of forces acting in pairs has an important connection to conservation laws. If we apply the concept correctly, we should discover a way to preserve momentum, energy or any other similar quantity.

There are different types of forces that go hand in hand. Whenever a physical force is present such as gravity or friction, there is usually another unseen force at play that allows it to happen. This could relate to electrical or magnetic forces for example.

Any form of propulsion requires the set-up of a pair of opposite forces. One provides the energy or pressure to get things moving while the other balances or counteracts them. It's for this reason why you need both friction and gravity to stay on your feet.

Force does not only act between material substances; it can also influence humans without us ever realising. For example, if someone gives you a compliment then rather than simply smiling, it’s likely that your own behaviour may subconsciously start shifting in order to show appreciation for that person.