# Shared Flashcard Set

## Details

Physics First Semester Exam
chap 1-11
65
Physics
12/18/2012

Term
 What is a derived unit?
Definition
 a unit that you get from combining fundamental units
Term
 What are the fundamental units of the MKS system?
Definition
 meter kilogram second
Term
 number of significant digits in 400,000
Definition
 1
Term
 number of signifcant digits in 40.01
Definition
 4
Term
 number of significant digits in .00203
Definition
 3
Term
 number of significant digits in 1.070
Definition
 4
Term
 when you add or subtract exponents, what has to happen?
Definition
 the exponents have to be the same number
Term
 What is the difference between precision and accuracy?
Definition
 precision is the degree of exactness of a measurment whereas accuracy describes how well the results of the meausrement agree with the "real" value
Term
 What are the three major graphical relationships and their equations?
Definition
 direct--y=kx; inverse--y=k/x; exponential--y=kx^2
Term
 What is the difference between a scalar and a vector? examples of each.
Definition
 a scalar has magnitude only; a vector has magnitude and direction; scalar example is speed; vector example is velocity
Term
 Vectors are represented by_____.
Definition
 arrows
Term
 What is the difference in distance and displacement?
Definition
 distance is how far you go with no direction; displacement is how far you are from where you began
Term
 What is the difference in speed and velocity?
Definition
 speed is how fast you are going; velocity is how fast you are going in a particular direction
Term
 What is Galileo's law of falling bodies?
Definition
 all objects fall with the same acceleration (9.8 m/s^2) in the absence of air resistance
Term
 What is the value for "g" on earth?
Definition
 9.8
Term
 What does the slope of a d-t graph represent?
Definition
 velocity; the steeper the slope, the greater the velocity
Term
 What does a flat line on a position time graph mean?
Definition
 the person is stopped
Term
 What does the slope of a velocity time graph represnet?
Definition
 acceleration
Term
 What does a flat line on a velocity time graph mean?
Definition
 he going at a constant velocity
Term
 What is a force?
Definition
 interaction between two objects
Term
 What are the fundamental forces?
Definition
 electromagnetic, gravity, weak nuclear, strong nuclear
Term
 Newton's first law
Definition
 the law of inertia; an object a rest will remain at rest and an object in motion will remain in motion at a constant speed in a straight line unless acted on by an outside force
Term
 Newton's second law
Definition
 the law of acceleration; acceleration is directly propotional to net force and inversely proportional to mass
Term
 Newton's third law
Definition
 to every action, there is an equal and opposite reaction; there are two forces and two objects
Term
 What is inertia?
Definition
 the ability of an object to remain at rest or stay in motion
Term
 What is the difference in mass and weight?
Definition
 mass is a scalar and it is teh amount of matter or the amount of inertia; weight is the force of gravity, vector, downwards, measured in Newtons.
Term
 What is a projectile?
Definition
 anything that's tossed, thrown, or dropped in a gravitational field
Term
 What component stays constant during the flight of a projectile?
Definition
 x component
Term
 What velocity component is affected by the acceleration of gravity?
Definition
 y component
Term
 What is the first step in solving a horizontally shot projectile?
Definition
 find time first
Term
 If an object is thrown horizontally and another object is dropped at the same time, which object will hit first?
Definition
 they will hit at the same time
Term
 What is uniform circular motion? Is an object in uniform cicular motion accelerating?
Definition
 when an object is moving in a circular path at a constant speed; yes because it changes direction
Term
 What causes an object to follow a circular path? What is the equation?
Definition
 centripetal force; Fc=mv^2/r
Term
 What are Kepler's three laws?
Definition
 all planets more about the sun in ellipses; a planet speeds up as it apporaches the sun; the ration of the period squared to the radius cubed is constant
Term
 What is the universal law of gravitation?
Definition
 the force of gravity is directly proportional to the products of the masses and inversely proportional to the distance squared
Term
 Who determined the universal gravitational constant?
Definition
 Henry Kavendish
Term
 What is the inverse square law?
Definition
 double the distance, the inverse square is 1/4
Term
 If a person weighed 750 N on earth and went to a planet that was 5 times more massive and twice the radius of Earth, what would he weigh on the planet?
Definition
 750(5)=3750(1/4)-937.5 N
Term
 What is rotational motion and how is it caused?
Definition
 motion in a circle surrounding an axis; caused by torque
Term
 What is torque?
Definition
 rotational effect caused by parallel forces
Term
 How do you calculate torque?
Definition
 T=Fl; l is the torque arm, which is the perpendicular length from the pivot point to the force
Term
 What determines how much rotational inertia something has?
Definition
 the distribution of mass; the big wheel has more rotational inertia than the small wheel
Term
 What is rotational inertia or moment of inertia?
Definition
 when an object starts rotating, it wants to kepp rotating;
Term
 What is the center of mass (gravity) of an object?
Definition
 the point at which you draw your force vector down; where the force of gravity acts
Term
 When will toppling occur?
Definition
 when the center of gravity is not over the base of support
Term
 What are the 2 conditions of equilibrium?
Definition
 translational and rotational; translational--Fup=Fdown; rotational--CW torque=CCW torque; both of these conditions must be met to be in equlibrium
Term
 What is momentum?
Definition
 inertia in motion; determined by mass and velocity
Term
 What is impulse?
Definition
 the amount of force and the amount of time the force is applied to an object
Term
 What is the law of conservation of momentum?
Definition
 the total momentum in a system remains constant
Term
 What is work? What is the unit of work?
Definition
 a force acting through a distance; joule (newton-meter)
Term
 What must be true about the force and distance for work to be done?
Definition
 the force must cause motion parallel to the direction of the force for work to be done
Term
 What is power? What is the unit of power?
Definition
 rate of doing work or how fast work is done; Watt
Term
 What is energy? What is the unit of energy?
Definition
 the ability to do work; joule
Term
 HOw do you calculate gravitation poential energy?
Definition
 mass x gravity x height
Term
 what happens when forces are balanced?
Definition
 they add up to zero and will not cause a change in motion
Term
 what happens when forces are unbalanced?
Definition
 they will not add to zero and will not cause a change in motion
Term
 hwo do you find the direction after using the pythagorean theorem?
Definition
 inverse tan of opposite over adjacent then write east of south
Term
 Vy component is always ____.
Definition
 vertical
Term
 What is the universal gravitation constant (G)?
Definition
 6.67 x 10^-11
Term
 what are the first steps in solving a horizontally shot projectile?
Definition
 find time first
Term
 If the distance between two objects is tripled, then what happens to the gravitational force between them?
Definition
 1/9
Term
 What happens if the mass of one object is doubled?
Definition
 force would double
Term
 What is the critical velocity?
Definition
 how fast something must be going to make it around the loop
Term
 What does a flat line on a distance time graph mean?
Definition
 the person is stopped
Term
 What does a flat line on a velocity time graph mean?
Definition
 constant acceleration
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