Imagen de un cúmulo de galaxias tomada por el telescopio Hubble. Fuente: NASA
The interactions that occur on a body may seem complicated at first sight, but the fundamental forces of Nature are actually only four: Fundamental forces Strong nuclear force Atomic nuclei
Weight is the gravitational force that the Earth exerts on bodies that are close to its surface. Suppose a body of mass m is close to the surface of the
The contact forces are those for which the body that exerts the force is in direct contact with the body on which this force acts. Although the only forces of
The normal force (N) is the component of the contact force that is perpendicular to the surface that an object contacts. When an object is placed on another, the electrical
The surface of objects is usually rough. This is the reason why when two objects are in contact and one of them is in relative motion (or begins to move)
Image of the Earth-Moon system taken by Galileo in 1992. Source: NASA.
After stating the laws of the motion of bodies, Newton wondered what was the force responsible for the elliptical orbits described by the planets around the Sun. In his book
Tension is the force transmitted by a rope, a string, a cable, a wire, a chain, etc … when one pulls from its ends. The tension is directed along the
A compressed or stretched spring exerts a restoring force on a mass attached to it. The restoring force always acts opposite to the deformation of the spring to bring the