Glossary in Objective-C

Generation QR in Objective-C Glossary

machine (266): A tool that makes work easier (but does not change the amount of work) by changing the magnitude or the direction of the force exerted to do work magnetic field (645): The area around a magnet, or around any current-carrying wire or coil of wire, where a magnetic force exists

nearsightedness (501): A vision defect in which a person cannot see distant objects clearly because images are focused in front of the retina; can be corrected with a concave lens net force (92): The vector sum of all the forces on an object neutral (543): An atom whose positively charged nucleus exactly balances the negative charge of the surrounding electrons Newton s first law (94): States that an object at rest will remain at rest, and a moving object will continue moving in a straight line with constant speed, if and only if the net force acting on that object is zero Newton s second law (93): States that the acceleration of an object is proportional to the net force and inversely proportional to the mass of the object being accelerated Newton s second law for rotational motion (208): States that the angular acceleration of an object is directly proportional to the net torque and inversely proportional to the moment of inertia Newton s third law (102): States that all forces come in pairs and that the two forces in a pair act on different objects and are equal in strength and opposite in direction node (389): The stationary point where two equal wave pulses meet and are in the same location, having a displacement of zero

normal (391): The line in a ray diagram that shows the direction of the barrier and is drawn at a right angle, or perpendicular, to the barrier normal force (107): The perpendicular contact force exerted by a surface on another object nuclear reaction (807): Occurs when the number of neutrons or protons in a nucleus changes; can be produced by bombardment of nuclei by gamma rays, other nuclei, protons, neutrons, alpha particles, or electrons nucleons (802): Protons and neutrons nucleus (749): The tiny, massive, positively charged central core of an atom nuclide (801): The nucleus of an isotope

object (461): A luminous or illuminated source of light rays that are to be reflected by a mirrored surface observed light frequency (446): The frequency of light as seen by an observer opaque (433): A medium that absorbs light and reflects some light rather than transmitting it, preventing objects from being seen through it open-pipe resonator (412): A resonating tube with both ends open that also will resonate with a sound source; its resonant frequencies are whole-number multiples of the fundamental origin (34): The point at which both variables in a coordinate system have the value zero

pair production (820): The conversion of energy into a matterantimatter pair of particles parallel circuit (623): A type of electric circuit in which there are several current paths; its total current is equal to the sum of the currents in the individual branches, and if any branch is opened, the current in the other branches remains unchanged parallel connection (600): A type of connection in which the circuit component and the voltmeter are aligned parallel to one another in the circuit, the potential difference across the voltmeter equals the potential difference across the circuit element, and there are two or more current paths to follow particle model (33): A simplified version of a motion diagram in which the moving object is replaced by a series of single points pascal (342): The SI unit of pressure Pascal s principle (352): States that any change in pressure applied at any point on a confined fluid is transmitted undiminished throughout the fluid pendulum (378): A device that can demonstrate simple harmonic motion when its bob (a massive ball or weight), suspended by a string or light rod, is pulled to one side and released, causing it to swing back and forth period (375): In any periodic motion, the amount of time required for an object to repeat one complete cycle of motion periodic motion (375): Any motion that repeats in a regular cycle periodic wave (381): A mechanical wave that moves up and down at the same rate photoelectric effect (726): The emission of electrons by certain metals that is produced when they are exposed to electromagnetic radiation photon (727): A discrete, quantized bundle of radiation that travels at the speed of light, has zero mass, and has energy and momentum

physics (3): The study of matter and energy and their relationships piezoelectricity (711): The property of a crystal that causes it to bend or deform, producing electric vibrations, when a voltage is applied across it pitch (406): The highness or lowness of a sound wave, which depends on the frequency of vibration plane mirror (461): A flat, smooth surface from which light is reflected by regular reflection, producing a virtual image that is the same size as the object, has the same orientation, and is the same distance from the mirror as the object plasma (348): A gaslike, fluid state of matter made up of negatively charged electrons and positively charged ions that can conduct electricity; makes up most of the matter in the universe, such as stars polarization (443): Light whose waves oscillate only in a single plane (644): For a magnet, describes the property of having two distinct, opposite ends, one of which is a northseeking pole and the other of which is a south-seeking pole position (34): The separation between an object and the origin; it can be either positive or negative position-time graph (38): A graph that can be used to determine an object s velocity and position, as well as where and when two objects meet, by plotting the time data on a horizontal axis and the position data on a vertical axis power (263): The work done, divided by the time needed to do the work precision (12): A characteristic of a measured value describing the degree of exactness of a measurement pressure (342): The force on a surface, divided by the surface s area primary coil (682): An electrically insulated transformer coil, which, when connected to an AC voltage source, induces an alternating EMF in the secondary coil primary color (440): Red, green, and blue, which can be combined to form white light and mixed in pairs to produce the secondary colors: yellow, cyan, and magenta primary pigment (441): Cyan, magenta, and yellow, each of which absorbs one primary color from white light and reflects two primary colors; can be mixed in pairs to produce the secondary pigments: red, green, and blue principal axis (464): A straight line perpendicular to the surface of a mirror that divides the mirror in half principle of superposition (388): States that the displacement of a medium caused by two or more waves is the algebraic sum of the displacements of the individual waves principal quantum number (755): The integer, n, that determines the quantized values of r and E for an electron s orbital radius in hydrogen and the energy of a hydrogen atom the radius, r, increases as the square of n, whereas the energy, E, depends on 1/n2 projectile (147): An object shot through the air, such as a football, that has independent vertical and horizontal motions and, after receiving an initial thrust, travels through the air only under the force of gravity