A force is a push or pull that acts upon an object as a result of that objects interactions with its surroundings. In this Lesson, The Physics Classroom details that nature of these forces, discussing both contact and non-contact forces. A force is a push or pull that acts upon an object as a result of that objects interactions with its surroundings. In this Lesson, The Physics Classroom differentiates between the various types of forces that an object could encounter. In physics, a force is an action that can cause an object to change its velocity or its shape, or to resist other forces, or to cause changes of pressure in a fluid. In mechanics, force makes ideas like pushing or pulling mathematically precise. The force on an object equals the object’s mass multiplied by its acceleration. When one object exerts a force on another object, the second object exerts an equal and opposite force on the first. Some common synonyms of force are coerce, compel, constrain, and oblige. While all these words mean to make someone or something yield, force is the general term and implies the overcoming of resistance by the exertion of strength, power, or duress. Force, in mechanics, any action that tends to maintain or alter the motion of a body or to distort it. The concept of force is commonly explained in terms of Isaac Newton’s three laws of motion. Because force has both magnitude and direction, it is a vector quantity. 1. In full strength; in large numbers: Demonstrators were out in force. 2. In effect; operative: a rule that is no longer in force. force, compel, coerce, constrain, oblige mean to make someone or something yield. force is the general term and implies the overcoming of resistance by the exertion of strength, power, or duress. The strength of a force is measured in newtons (N). There are four fundamental forces in physics. A force is always a push, pull, or a twist, and it affects objects by pushing them up, pulling them down, pushing them to a side, or by changing their motion or shape in some other way. Force and Energy: A Dynamic Duo Force and energy are intimately connected. Force does work when it causes displacement. The amount of work done is the product of force and the distance over which it acts, assuming the force is constant and acts along the direction of motion. This relationship leads directly to kinetic energy and potential energy.