Reviewer Midterms PDF

Reviewer **Physics is** the scientific study of matter and energy and how they interact with each other. **Physics** is the study of the properties, behavior and interaction between matter and energy. **Physics** is the study of natural phenomena. **Physics** is the study that investigates and f...

Reviewer **Physics is** the scientific study of matter and energy and how they interact with each other. **Physics** is the study of the properties, behavior and interaction between matter and energy. **Physics** is the study of natural phenomena. **Physics** is the study that investigates and formulates the fundamental laws of nature. **Matter i**s any substance which has mass and occupies space. **Photons** have no mass, so they are an example of something in physics is not comprised of matter. They are also not considered \"objects\" in the traditional sense, as they cannot exist in a stationary state. **Acoustics** - the study of sound & sound waves **Astronomy** - the study of space **Astrophysics** - the study of the physical properties of objects in space **Atomic Physics** - the study of atoms, specifically the electron properties of the atom **Biophysics** - the study of physics in living systems **Chaos** - the study of systems with strong sensitivity to initial conditions, so a slight change at the beginning quickly become major changes in the system **Chemical Physics** - the study of physics in chemical systems **Computational Physics** - the application of numerical methods to solve physical problems for which a quantitative theory already exists **Cosmology** - the study of the universe as a whole, including its origins and evolution **Cryophysics / Cryogenics / Low Temperature Physics** - the study of physical properties in low temperature situations, far below the freezing point of water **Crystallography** - the study of crystals and crystalline structures **Electromagnetism** - the study of electrical and magnetic fields, which are two aspects of the same phenomenon **Electronics** - the study of the flow of electrons, generally in a circuit **Fluid Dynamics / Fluid Mechanics** - the study of the physical properties of \"fluids,\" specifically defined in this case to be liquids and gases **Geophysics** - the study of the physical properties of the Earth **High Energy Physics** - the study of physics in extremely high energy systems, generally within particle physics **High Pressure Physics** - the study of physics in extremely high pressure systems, generally related to fluid dynamics **Laser Physics** - the study of the physical properties of lasers **Mathematical Physics** - applying mathematically rigorous methods to solving problems within physics **Mechanics** - the study of the motion of bodies in a frame of reference **Meteorology / Weather Physics** - the physics of the weather **Molecular Physics** - the study of physical properties of molecules **Nanotechnology** - the science of building circuits and machines from single molecules and atoms **Nuclear Physics** - the study of the physical properties of the atomic nucleus **Optics / Light Physics** - the study of the physical properties of light **Particle Physics** - the study of fundamental particles and the forces of their interaction **Plasma Physics** - the study of matter in the plasma phase **Quantum Electrodynamics** - the study of how electrons and photons interact at the quantum mechanical level **Quantum Mechanics / Quantum Physics** - the study of science where the smallest discrete values, or quanta, of matter and energy become relevant **Quantum Optics** - the application of quantum physics to light **Quantum Field Theory** - the application of quantum physics to fields, including the fundamental forces of the universe **Quantum Gravity** - the application of quantum physics to gravity and unification of gravity with the other fundamental particle interactions **Relativity** - the study of systems displaying the properties of Einstein\'s theory of relativity, which generally involves moving at speeds very close to the speed of light **Statistical Mechanics** - the study of large systems by statistically expanding the knowledge of smaller systems **String Theory / Superstring Theory** - the study of the theory that all fundamental particles are vibrations of one-dimensional strings of energy, in a higher-dimensional universe **Thermodynamics** - the physics of heat **Natural Science -** is the systematic study of phenomena **Natural Science -** is the systematic study of phenomena occurring in the material universe and the laws governing them. **Physical Science** deals with matter and energy. Under this, we have the study of the composition, structure, properties and classification of matter (Chemistry and Physics). **Scientific method** refers to the principles and processes that guide scientific investigation. It provides the framework within which scientists try to discover the laws governing the observable world. It also regulates the manner in which their inquiries are concluded. **Theory -** a probable, logical explanation or reason for related events. Law- a principle, a proven and accepted theory, a statement, an explanation or description of the event. **Precision** in a strict sense refers to the repeatability of the measurement using a given instrument. **Accuracy** refers to how close a measurement is to the true value. **meter (m)** - The base unit of length **kilogram (kg)** - The base unit of mass **second (s)** - The base unit of time **ampere (A)** - The base unit of electrical current **Kelvin(degrees K)** - The base unit of thermodynamic temperature; **mole (mol)** - The base unit of substance; **candela (cd)** - The base unit of luminous intensity **Percentage Error --** This is used in determining the percentage of discrepancy between a value gathered from an experiment and the standard or accepted value. **Percentage Difference --** This is used if you are comparing an experimental parameter derived from two different method. **vector quantity** is a quantity which is fully described by both magnitude and direction. **scalar quantity** is a quantity which is fully described by its magnitude. **resultant** is the vector sum of two or more vector. **Kinematics --** describes the motion of objects without explicit reference to any forces. It describes how objects move. **Dynamics --** deals with forces and their effect on motion. **Motion** -- is defined as the displacement of an object in relation to objects that are considered to be stationary. Motion is relative displacement. **Distance** -- refers to the total path length traversed in moving from one location or point to another. **Displacement** -- is a change of position in a particular direction. Displacement is a vector quantity with both magnitude and direction. **Difference between distance and displacement** **Distance and displacement** are two quantities which may seem to mean the same thing, yet they have distinctly different meanings and definitions. **Distance** is a scalar quantity which refers to \"how much ground an object has covered\" during its motion. **Displacement** is a vector quantity which refers to \"how far out of place an object is\"; it is the object\'s change in position. **Speed** is a scalar quantity which refers to \"how fast an object is moving.\" **Velocity** is a vector quantity which refers to \"the rate at which an object changes its position.\" Speed is the rate of change of ***distance*** with time. Velocity is the rate of change of ***displacement*** with time. Any change in the velocity of an object results in an acceleration **Force -** is a vector quantity defined to be either a push or a pull. **Free Body Diagram (FBD) --** are illustrations exposing the external forces acting on a body that is isolated from the universe. **Mass --** the amount of matter in a body. It is always constant. **Weight --** is the pull of the earth in a body. It is dependent on the location of the body with respect to the gravitational source. Weight is always directed downwards. **W = mg** **Contact Force --** is a compressive force that exists whenever two bodies come into contact with each other. It is also called **Normal Force** because it is always perpendicular to the surface of contact. **Friction --** is a force that impedes motion. Since it tends to prevent the motion of the body along the surface of contact, it is parallel to the contact surface and is against the motion or the probable motion of the body. **Static Friction --** occurs if there is no change in motion of a body. **Kinetic Friction --** occurs if there is a change in motion in a body. **Support Forces --** are forces that occur due to devices that keep objects in a desired position like that of a string or a hinge. **Inertia --** is the tendency of object to maintain their state of rest of uniform motion. **Equilibrium --** state of being balance. **Translational equilibrium --** exists when there is no resultant force acting on a body at about any given axis. **Static equilibrium --** exists when the body is at rest. **Dynamic equilibrium --** exists when the body is moving at a constant speed along a straight path. **Friction** refers to the resistance which opposes every effort to slide or roll one body over another. It is caused by the adhesion of one surface to the other and interlocking of irregularities of the rubbing surfaces. **CLASSES OF FRICTION FORCES** **1. Static Friction -** the frictional force exerted by one surface on another where there is no relative motion of the two surfaces. **2. Kinetic Friction --** the frictional force exerted by one surface on another when one surface slides over the other. **3. Rolling Friction -** the frictional force that opposes one body rolling over another owing to the constant deformation of the surfaces in contact. **4. Fluid friction --** the property called viscosity of liquids and gases to offer resistance to objects moving through them. **Advantages of Friction**  Walking would be impossible without it  The usefulness of brakes, matches, nails and screws depends on it  Prevents belts from slipping off their pulleys  Friction between tires and roads prevents skidding  Friction clutches enables gas engines to start under a load **Disadvantages of friction**  It causes wearing out of parts  It results in loss of work thus reducing efficiency  It produces heat which may cause expansion of the machine **Factors Affecting Friction** **1. Velocity --** friction decreases somewhat with increasing speed, thus starting (static) friction is greater than sliding (kinetic) friction but sliding is independent of velocity. **2. Normal Force --** friction increases with the increasing perpendicular force with which either surface is pressed against the other. **3. Nature and condition of the rubbing surface --** friction is less when the surfaces are hard and smooth. **4. Area of contact --** for dry surfaces, friction is particularly independent of the area in contact, but with wet lubricated surfaces, friction is nearly proportional to the area in contact. **Ways of reducing friction** 1\. Lubrication 2\. Smoothing and polishing the contact surfaces 3\. Using anti friction metals 4\. Using unlike metals for contact surfaces 5\. Using ball bearings or roller bearings. **UNIFORM CIRCULAR MOTION-** when a particle moves in a circle with a constant speed **PROJECTILE -** motion of a body along a curve path **TRAJECTORY --** the path followed by a projectile