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Physics: Units 5-9
Term | Definition |
---|---|
Momentum | quantity defined as the product of the mass and velocity of an object |
Impulse | product of force and time over which a force acts |
Impulse-Momentum Theorem | I=Fnet x delta t= delta p |
Law of Conservation of Momentum | the total momentum of all objects interacting with one another remains constant regardless of the nature of the forces between the objects |
Inelastic Collision | a collision in which two objects stick together completely after colliding |
Elastic Collision | a collision in which the total momentum and KE is conserved (objects bounce off one another with no permanent deformation) |
Rotational Motion | movement in a circle or spinning |
Radian | angle formed when an arc length is equal to the radius of a circle |
Revolution | one time around the radius of a circle |
Angular Displacement | change in an angle (delta theta) |
Tangential Speed | the linear speed of something moving in a circular path |
Angular Speed | rate at which an object moves through an angle |
Centripetal Force | net force acting toward the center of a circle keeping an object moving in a circular path |
Tangential Acceleration | how the tangential velocity of a point changes with time (same as linear acceleration but is specific to tangential direction) |
Angular Acceleration | rate of change in angular speed |
Rotational Kinematics | applying kinematics equations to rotational problems |
Centripetal Acceleration | acceleration towards the center of a circle |
Centrifugal Force | imaginary outward force felt by observers moving in a circular path |
Newton's Law of Universal Gravitation | F=(GxM1xM2)/r squared |
Universal Gravitation Constant | 6.67408x10 to the -11 power |
Kepler's Second Law of Planetary Motion | an imaginary line drawn from the sun to any planet sweeps out equal areas in equal time intervals |
Kepler's Third Law of Planetary Motion | The square of a plant's orbital period is proportional to the cube of the average distance between the planet and the sun |
Black Hole | a region of space having a gravitational field so intense that no matter can escape |
Kepler's 1st Law of Planetary Motion | Each planet travels in an elliptical orbit around the sun with the sun at one of its focal points |
Center of Gravity | the point at which the mass of a body can be considered to be concentrated when analyzing translational motion |
Torque | a quantity that measures the ability of a force to rotate an object about some axis |
Lever Arm | r(sin of theta) or d(sin of theta) |
Rotational Equilibrium | when the net force equals zero |
Moment of Inertia | tendency of an object to resist a change in rotational motion |
Angular Momentum | product of the moment of inertia and the angular velocity |
Conservation of Angular Momentum | lowering the moment of inertia will increase the rotational speed |
Translational Kinetic Energy | KE=1/2(m)(v squared) |
Rotational Kinetic Energy | KE=1/2(I)(w squared) |
Fluid | a non-solid state of matter in which the atoms or molecules are free to flow |
Mass Density | concentration of matter in an object |
Buoyant Force | upward force exerted by a fluid on an object that is sitting in or floating on a fluid |
Pressure | magnitude of the force on a surface per unit of area |
Ideal Fluid | a fluid with no internal friction |
Archimedes' Principle | an object completely or partially submerged in a fluid experiences an upward buoyant force equal in magnitude to the weight of the fluid displaced by the object |
Pascal's Principle | pressure applied to a fluid in a closed container is transmitted equally to every point in the fluid as well as the walls of the container |
Venturi Effect | the speed of a fluid increases when the cross sectional area decreases |
Flow Rate | product of area times volume for fluid in a pipe |
Bernoulli's Principle | the pressure of a fluid decreases as the velocity of a fluid increases |
Ideal Gas Law | (P1V1)/T1=(P2V2)/T2 |
Temperature | the measure of the average KE of the particles of the substance |
Internal Energy | the energy of a substance due to both the random motion of its particles and to the potential energy that results from the distances and alignments of the particles |
Thermal Equilibrium | the state in which two physical bodies in contact with each other have identical temperatures |
Heat | energy transferred between objects because of a difference in temperature |
Specific Heat Capacity | the quantity of heat required to raise a unit of mass of homogeneous material by 1K or 1C given constant pressure and volume |
Calorimetry | an experimental procedure used to measure the energy transferred from one substance to another as heat |
Phase Change | physical change in a substance from one state of matter to another at constant temperature and pressure |
Latent Heat | the energy per unit of mass that is transferred during a phase change |
Hooke's Law | the restoring force of a string depends on the stiffness of the spring and the displacement from the string's equilibrium point |
Simple Harmonic Motion | vibration about an equilibrium position in which a restoring force is proportional to the displacement from the equilibrium |
Medium | physical environment through which a disturbance can travel |
Mechanical Waves | a wave that requires a medium to travel through (sound waves) |
Pulse Wave | a wave that consists of a single traveling pulse |
Transverse Wave | a wave whose particles vibrate perpendicularly to the direction that the wave is traveling |
Compressional Wave | a wave whose particles vibrate parallel to the direction that the wave is traveling |
Compression | region of a longitudinal wave where the pressure and density are at a maximum |
Rarefraction | region of a longitudinal wave where the pressure and the density are at a minimum |
Constructive Interference | a combining of two or more waves that results in a wave that is a sum of the two colliding crests/ troughs |
Destructive Interference | a combining of two waves that results in the waves and troughs canceling each other out to create either a smaller wave or no wave at all |
Infrasonic Waves | sound waves with frequencies below 20 Hz |
Ultrasonic Waves | sound waves with frequencies above 20,000 Hz |
Pitch | a measure of how high or low the sound is perceived to be, depending on the frequency |
Doppler Effect | an observed change in frequency when there is relative motion between the source of waves and the observer |
Intensity | the rate at which energy flows through a unit perpendicular to the direction of wave motion |
Decibel | a dimensionless unit that describes the ratio of two intensities of sound |
Resonance | a phenomenon that occurs when the frequency of a force applied to an object matches the natural frequency; resulting in a large amplitude of vibration |
Fundamental Frequency | the lowest frequency of vibration in a standing wave |
Harmonic Series | a series of frequencies that includes the fundamental frequency and successive harmonics |
Timbre | the musical quality of a tone resulting in the combination of harmonics present at different intensities |
Beat | periodic variation in amplitude of a wave that is the superposition of two waves of slightly different frequencies |
Reverberation | prolongation of a sound |
Electromagnetic Wave | a wave consisting of oscillating electric and magnetic fields, which radiate outward from the source at the speed of light |
Luminous Flux | rate at which light is emitted from a source (measured in lumens) |
Illuminance | luminous flux divided by surface area |
Reflection | the change in direction of an electromagnetic wave at a surface that causes it to move away from the surface |
Virtual Image | an image where light rays appear to diverge even though they aren't actually focused there; cannot be projected onto a screen |
Concave Spherical Mirror | a mirror whose reflecting surface is a segment from the inside of a sphere |
Real Image | an image formed by intersecting of light rays; can be projected onto a screen |
Paraxial Rays | light rays that are near to the principal axis of a mirror and are used in ray diagrams |
Spherical Aberration | a blurred image resulting from a spherically shaped mirror |
Magnification | the process of enlarging something in appearance rather than physical size |
Convex Spherical Mirror | a mirror with a reflecting surface of an outward-curved segment of a sphere |
Linear Polarization | the alignment of electromagnetic waves in such a way that the vibrations of the electric fields in each of the waves are parallel to each other |
Refraction | the bending of a wave front as a wave passes between two substances in which the speed of the wave differs |
Index of Refraction | the ratio of the speed of light in a vacuum to the speed of light in a given transparent medium |
Snell's Law | n1sin(theta1)=n2sin(theta2) |
Lens | a transparent object that refracts light rays such that they converge or diverge to create an image |
Converging Lens | thick in the middle and thinner on the edges (convex) |
Diverging Lens | thin in the middle and thicker on the edges (concave) |
Total Internal Reflection | the complete reflection that takes place within a substance when the angle of incidence of light striking a surface boundary is greater than the critical angle |
Critical Angle | the angle of incidence at which refracted light makes an angle of 90 degrees with the normal |