Britannica
Sources used in this answer
How do Newton’s three laws of motion explain the movement of objects?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
principles of physical science
Figure 1: Data in the table of the Galileo experiment. The tangent to the curve is drawn at t = 0.6.
Newton’s laws of motion provide the foundation for classical mechanics, describing how forces influence the movement of objects.12
- First Law (Law of Inertia): An object remains at rest or in uniform motion in a straight line unless acted upon by an external force. This principle explains that motion is a natural state, and changes in that state require an unbalanced force, such as friction.123
- Second Law (F = ma): This law quantifies how a force changes an object's motion. It states that the time rate of change of momentum is equal to the applied force. For an object with constant mass, this is expressed as , meaning a net force causes acceleration in the direction of that force.12
- Third Law (Action and Reaction): When two bodies interact, they exert forces on each other that are equal in magnitude and opposite in direction. These forces act on different bodies and explain interactions in both static equilibrium and accelerated motion.12
Together, these laws allow scientists to predict the motion of objects by analyzing the balance or imbalance of forces acting upon them.12