Physics
Physics: Forces
Quick fact
Forces can be either contact forces (like friction) or field forces (like gravity), and they always act in pairs according to Newton’s third law.
Why this is interesting
Have you ever wondered why a ball rolls when you push it, or why you feel heavier in an elevator? These are all questions about forces.
Read the full explanation
Understanding Physics: Forces
A force is a push or pull that acts on an object. It can cause the object to speed up, slow down, change direction, or even deform. Forces are described by their magnitude and direction, which means they are vector quantities. When multiple forces act on an object, their combined effect determines how the object moves.
A deeper explanation
Forces arise from interactions between objects or fields. Contact forces occur when two objects touch directly (like pushing a book across a table), while field forces act at a distance without physical contact (like Earth’s gravitational pull). The effects of forces are explained by Newton’s laws: the first law describes inertia, the second law relates force, mass, and acceleration, and the third law states that for every action, there is an equal and opposite reaction. Understanding these principles allows us to predict motion and design everything from cars to space travel.