# Shared Flashcard Set

## Details

Physics and Human Affairs Test #1
N/A
12
Physics
02/10/2014

Term
 Atoms
Definition
 1.All substances are made from tiny (microscopic) particles, either atoms or molecules. 2.Unseen moving particles can have noticeable (macroscopic) effects like temperature, pressure and Brownian motion. 3.one micron: 1 μm = 10-6 m = 0.000001 m plus “E, P, T, G, M, K, m, μ, n, p, f, a” as well.
Term
 Chemical Reactions
Definition
 only involve electron transfer between atoms. the nucleus of each atom remains unchanged
Term
 Particles and Substances
Definition
 1. An element is a substance that can not be separated into different components (by chemical reactions). 2. An atom is the smallest particle of an element. 3. A molecule (CO2) is a particle that combines multiple atoms (C and O). 4.A compound (water) is a substance that combines different elements but not different molecules. 5. A molecule (H2O) is the smallest particle of a compound. 6. A mixture is a (mechanical) combination of different compounds.
Term
 Phases: Solid, Liquid, and Gas
Definition
 Solid: has a fixed shape, a fixed volume, and the molecular organization is close, evenly spaced, and firmly attached. Liquid: has no fixed shape, has a fixed volume, and the molecular organization is close, disordered, and mobile. Gas: has no fixed shape, no fixed volume, and the molecular organization is distant, disordered, and mobile.
Term
 Cause and Effect
Definition
 Macroscopic effect: Temperature, Microscopic cause: particle speed, and therefore higher temperature implies faster particles. Macroscopic effect: Pressure, Microscopic cause: particle collisions, and therefore higher pressure implies closer particles or faster particles.
Term
 Multiply and Divide
Definition
Term
Definition
Term
 How things move
Definition
 Any objects dropped together, fall together, unless there is a drag The law of inertia: a change in velocity requires a net force  Direction matters for velocity (vector) but not for speed (scalar) Instantaneous velocity changes during acceleration Distance (d), at constant speed (s): d=st Average speed s= d/t
Term
 Galileo
Definition
 any objects dropped together, fall together, unless there is air resistance (friction)
Term
 Inclined Plane
Definition
 a ball rolling down hill accelerates (gains speed) less steep? less acceleration in the limit of no slope, the speed is constant a ball rolling up hill decelerates (negative acceleration) a force (such as gravity) causes acceleration Constant velocity implies no force
Term
 Law of Inertia (Newton's first law)
Definition
 An object that is subject to no (net) external forces must maintain an unchanging (possibly zero) velocity (including direction). Constant velocity for no net force when push and friction exactly cancel. Net force (unbalanced friction) causes velocity to change (decrease). No net force always implies constant (possibly zero) velocity.
Term
 Circular Motion
Definition
 Circular motion at constant speed requires“centripetal” force. Speed is constant but velocity changes (direction). Give an angle or compass heading for direction
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