Vijay Shankar Sharma
Textbook physics terms. Not a BFUT reinterpretation. 371 terms. Textbook meanings only.
17 terms. Page 1 of 1.
particle · intermediate
A subatomic particle similar to the electron and muon but far more massive, roughly 3,477 times heavier than the electron, classified as a lepton and carrying the same negative electric charge. Discovered in 1975, the tau is unstable and decays extremely quickly, with a lifetime of about 2.9 times ten to the minus thirteen seconds, making it the heaviest of the three known charged leptons.
thermo · intro
A measure of the average kinetic energy of the particles within a substance, determining the direction of spontaneous heat flow between objects in contact; heat flows from higher to lower temperature until thermal equilibrium is reached. Temperature is measured using scales such as Celsius, Fahrenheit, and the absolute Kelvin scale, and it is a statistical property that only makes clear sense for systems containing many particles.
mechanics · intro
A pulling force transmitted through a flexible object such as a rope, cable, or string when it is pulled taut from both ends, directed along the length of the object and away from whatever it is attached to. Tension is a reactive force; it arises only in response to an applied pulling force and adjusts in magnitude to satisfy the physical constraints of the system, such as keeping an inextensible rope from stretching.
mechanics · intro
The constant maximum speed reached by an object falling through a fluid, such as air, when the resistive drag force acting upward exactly balances the downward pull of gravity, resulting in zero net acceleration. Once terminal velocity is reached, the object continues falling at that constant speed rather than continuing to accelerate. Terminal velocity depends on an object's mass, cross-sectional area, shape, and the density of the fluid it is falling through.
em · intro
The SI unit of magnetic field strength, or magnetic flux density, named after inventor and engineer Nikola Tesla. One tesla represents a fairly strong magnetic field; Earth's own magnetic field at its surface is only about 25 to 65 microteslas, while a typical refrigerator magnet produces roughly 0.001 tesla, and powerful MRI machines and particle accelerator magnets can reach several tesla.
thermo · intermediate
A material property describing how effectively it conducts heat, measured as the rate of heat transfer through a unit thickness of the material per unit temperature difference. Metals generally have high thermal conductivity due to their free-moving electrons, which efficiently transport thermal energy, while materials like foam, wood, and air have low thermal conductivity and are used as thermal insulators.
thermo · intro
The branch of physics concerned with heat, temperature, energy, and their relationships to work and the physical properties of matter, particularly in relation to macroscopic systems in or near equilibrium. Thermodynamics is built around a small number of foundational laws describing the conservation of energy, the tendency of entropy to increase, and the impossibility of reaching absolute zero, and it underlies the operation of engines, refrigerators, and countless natural processes.
mechanics · intermediate
A differential gravitational force that arises because different parts of an extended object experience slightly different gravitational pull from a nearby massive body, stretching the object along the line toward that body and compressing it perpendicular to that line. Tidal forces from the Moon and Sun cause Earth's ocean tides, and extreme tidal forces near a black hole can stretch and ultimately tear apart an object falling toward it, an effect sometimes called spaghettification.
relativity · intermediate
A consequence of special and general relativity in which time is measured to pass at different rates for observers in relative motion or experiencing different gravitational strengths. According to special relativity, a clock moving relative to an observer appears to run slower than a stationary one from that observer's perspective, while general relativity predicts that clocks closer to a massive object, in a stronger gravitational field, run slower than clocks farther away. Both effects have been confirmed experimentally.
mechanics · intro
A measure of the rotational effect of a force applied to an object, calculated as the force multiplied by the perpendicular distance from the axis of rotation to the line along which the force acts, commonly called the lever arm. Torque causes angular acceleration in the same way that ordinary force causes linear acceleration, and it explains why applying force farther from a hinge, such as at the handle of a door, makes it easier to open than pushing near the hinge itself.
optics · intermediate
An optical phenomenon in which a light ray traveling within a denser medium strikes the boundary with a less dense medium at an angle greater than a specific critical angle, causing all of the light to reflect back into the denser medium rather than refracting through the boundary. Total internal reflection is the physical principle that allows optical fibers to guide light over long distances with minimal loss, since the light continually reflects along the fiber's internal walls.
em · intro
An electrical device that transfers electrical energy between two or more circuits through electromagnetic induction, typically used to step voltage up or down while maintaining nearly constant power. A transformer consists of two coils of wire wound around a shared magnetic core; a changing current in the primary coil induces a changing magnetic field, which in turn induces a voltage in the secondary coil, with the ratio of voltages set by the ratio of the coils' turns.
quantum · intro
A semiconductor device used to amplify or switch electrical signals, consisting of three terminals through which a small current or voltage at one terminal controls a much larger current flow between the other two. Invented in 1947, the transistor replaced bulkier and less reliable vacuum tubes and became the fundamental building block of modern electronics, with billions of microscopic transistors now integrated into a single computer processor chip.
waves · intro
A wave in which the oscillation of the medium, or the oscillating field for electromagnetic waves, occurs perpendicular to the direction the wave travels. Light waves and waves traveling along a plucked string or shaken rope are common examples of transverse waves. This contrasts with longitudinal waves, such as sound, in which the oscillation occurs parallel to the direction of wave travel.
nuclear · intro
A radioactive isotope of hydrogen whose nucleus contains one proton and two neutrons, making it roughly three times as massive as ordinary hydrogen. Tritium decays through beta decay with a half-life of about 12.3 years and is used as fuel in certain nuclear fusion reactions, in self-powered lighting devices, and as a tracer in scientific research, though its radioactivity requires careful handling.
mechanics · intermediate
A chaotic, irregular pattern of fluid flow characterized by swirling eddies and rapid, unpredictable variations in velocity and pressure, occurring when a fluid's inertial forces dominate over its viscous forces, typically at high speeds or around obstacles. Turbulence stands in contrast to smooth, orderly laminar flow, and while it increases drag and mixing, it remains one of the most difficult phenomena in classical physics to predict precisely, despite being well described statistically.
cosmology · intro
A specific class of stellar explosion that occurs when a white dwarf star in a binary system accumulates enough mass, typically by pulling material from a companion star, to trigger a runaway thermonuclear explosion that completely destroys the white dwarf. Because these explosions consistently reach a similar peak intrinsic brightness, Type Ia supernovae serve as reliable standard candles for measuring cosmic distances, and their study in the late 1990s led to the discovery of the accelerating expansion of the universe attributed to dark energy.