Force

In physics, a force is any interaction that, when unopposed, will change the motion of an object. In other words, a force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate. Force can also be described by intuitive concepts such as a push or a pull. A force has both magnitude and direction, making it a vector quantity. It is measured in the SI unit of newtons and represented by the symbol F.

The original form of Newton's second law states that the net force acting upon an object is equal to the rate at which its momentum changes with time. If the mass of the object is constant, this law implies that the acceleration of an object is directly proportional to the net force acting on the object, is in the direction of the net force, and is inversely proportional to the mass of the object

Related concepts to force include: thrust, which increases the velocity of an object; drag, which decreases the velocity of an object; and torque, which produces changes in rotational speed of an object. In an extended body, each part usually applies forces on the adjacent parts; the distribution of such forces through the body is the so-called mechanical stress. Pressure is a simple type of stress. Stress usually causes deformation of solid materials, or flow in fluids.

Guru

Guru (Sanskrit: गुरु. IAST: guru) is a Sanskrit term that connotes someone who is a "teacher, guide or master" of certain knowledge. In pan-Indian traditions, guru is someone more than a teacher, traditionally a reverential figure to the student, with the guru serving as a "counselor, who helps mold values, shares experiential knowledge as much as literal knowledge, an exemplar in life, an inspirational source and who helps in the spiritual evolution of a student." The term also refers to someone who primarily is one's spiritual guide, who helps one to discover the same potentialities that the guru has already realized.

The oldest references to the concept of guru are found in the earliest Vedic texts of Hinduism. The guru, and gurukul – a school run by guru, were an established tradition in India by the 1st millennium BCE, and these helped compose and transmit the various Vedas, the Upanishads, texts of various schools of Hindu philosophy, and post-Vedic Shastras ranging from spiritual knowledge to various arts. By about mid 1st millennium CE, archaeological and epigraphical evidence suggest numerous larger institutions of gurus existed in India, some near Hindu temples, where guru-shishya tradition helped preserve, create and transmit various fields of knowledge. These gurus led broad ranges of studies including Hindu scriptures, Buddhist texts, grammar, philosophy, martial arts, music and painting.