# Shared Flashcard Set

## Details

Physics Chapter 1-3
Hewitt conceptual physics
15
Physics
11/18/2008

Term
 Size of Earth
Definition
 235 BC - Eratosthenes - measured a shadow at Alexandria and used information about Syene250,000 stadia in circumference
Term
 Size of Moon
Definition
 Aristarchus suggested Earth spns on daily axis.Calculated moon's diameter and distance from Earth in 240 BCE. Used lunar eclipse and coin to find distance to moon.
Term
 Scientific Method
Definition
 * Recognize question.* Make hypothesis.* Predict consequences of hypothesis.* Perform experiments or make calculations to test.* Formulate simplest general rule that organizes the hypothesis, predicted effects and experimental findings
Term
 Pseudoscience
Definition
 fake science which lacks evidence and cannot be proven wrong. Includes astrology, mysticism, energy multiplying machines.
Term
 Aristotle
Definition
 384-322 BC. Greek philosopher. "Natural motion proceeds from the nature of an object" (water, earth, air, fire). Believed heavier objects fell faster and this failure to recognize friction as a force impeded science for 2000 years.
Term
 Copernicus
Definition
 Polish astronomer, 1474-1543.Heliocentricism.
Term
 Galileo
Definition
 1564-1642, Pisa. Discovered that except for the small effect of air resistance, objects of various weights fall at same rate. Used balls and tilted planes to demonstrate friction.
Term
 Newton's First Law of Motion
Definition
 Every object continues in state of motion or rest in straight line unless force acted on it. INERTIA: the property of objects to resist changes in motion
Term
 Equilibrium Rule
Definition
 tension: a stretching force- when something hangs from spring, tension force acting upward and weight acting downward are equal and opposite (rest). Mechanical equilibrium: net force = 0. Σ F = 0. "vector sum of force = 0"
Term
 Speed
Definition
 Distance / Time
Term
 Vector vs. Scalar
Definition
 Vector Quantity specifies direction and magnitude (force, velocity)Scalar Quantity measures only magnitude (speed)
Term
 Acceleration
Definition
 change in velocity / time interval
Term
 Acceleration on Galileo's inclined planes
Definition
 Ball rolls with unchanging acceleration.Velocity acquired = acceleration x time.Steeper inclines result in greater accelerations.
Term
 Free fall
Definition
 10 m/s/sV = GT (velocity acquired = acceleration x time)
Term
 Distance traveled during Free Fall
Definition
 D = (1/2) g t^2
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