ACT科学术语
2015-10-11 10:31:15
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P319
Acceleration—The rate that velocity changes per unit time and the direction it changes in Computed from
the change in
P319
Acceleration—The rate that velocity changes per unit time and the direction it changes in. Computed from
the change in velocity divided by the change in time. Common units are meters per second squared (m/s2).
Acceleration due to gravity—The acceleration of an object that is only acted on by the force of the Earth’s
gravity. This value is given the symbol g and near the surface of the Earth it has a value of approximately
9.8 m/s2. The direction of the acceleration due to gravity is vertically downward.
Accuracy—The closeness of an experimental measurement to the accepted or theoretical value.
Acid—A substance that is a proton donor. The pH of an acid is less than 7.
Analysis—A stage in the scientific method where patterns of observations are made.
Aqueous solution—A solution in which the solvent is water.
Arteries—The vascular tissue which carries blood away from the heart.
Astronomy—The study of planets, stars, and space.
Atom—The smallest structure that has the properties of an element. Atoms contain positively charged protons
and uncharged neutrons in the nucleus. Negatively charged electrons orbit around the nucleus.
ATP—(Adenosine Triphosphate)—A chemical that is considered to be the “fuel” or energy source for an
organism.
Atria—The chambers of the heart that receive blood.
Base—A substance that is a proton acceptor. The pH of a base is greater than 7.
Calibration—The examination of the performance of an instrument in an experiment whose outcomes are
known, for the purpose of accounting for the inaccuracies inherent in the instrument in future experiments
whose outcomes are not known.
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