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29 Cards in this Set
- Front
- Back
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length
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meter [m]
measurement of space direction |
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time
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second [s]
continuous forward flowing of events |
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mass
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kilogram [kg]
amount of matter |
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electric current
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Ampere [A]
property of matter |
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temperature
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Kelvin [K]
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intensity of light
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Candela [cd]
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Speed
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Object travels divided by the time it takes to travel that distance.
Speed(in m/s) = distance (in m) / time (in s) s = d / t |
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Velocity
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has the same numerical value as speed but velocity always includes information on the direction of travel. The speed of a car may be 50 km per hour, while the velocity is 50 km per hour due west. This means velocity has a magnitude and a direction.
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Acceleration
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is the amount of change in velocity divided by the time it takes the change to occur.
acceleration( in m/s2)= [final velocity - initial velocity (in m/s)] / time ( in s) a = (vf - vi) / t |
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The First Law:
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An object in motion stays in motion until acted on by a force.
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The Second Law:
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The greater the force, the greater the acceleration; but the more massive the object being acted or by a given force, the smaller the acceleration.
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The Third Law:
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whenever a force is applied to an object, that object simultaneously exerts an equal and opposite force
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uniform motion
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if it travels in a straight line at constant speed.
All other motions are called accelerated |
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Newton's law of universal gravitation .
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Between any two objects in universe there is an attractive force (gravity) that is proportional to the masses of the objects and inversely proportional to the distance between them.
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Gravity
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force (= m * a)
g=9.81 m/s2 |
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Weight
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mass * acceleration from gravity
W = m * g force (in N) |
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Inertia
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is the tendency of an object to resist any change in its motion. Inertia is directly related to how much mass an object has -- how much stuff is there.
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Force
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mass * acceleration
N = kg m /s^2 |
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Work
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Work is equal to the force that is exerted times the distance over which it is exerted
In equation form: work (in Joules) = force (in Newtons) * distance (in meters) |
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Energy
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ability to do work
J power * time |
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Power
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is defined as the rate at which work is done, or at which energy is expended.
In words: Power is the amount of work done, divided by the time it takes to do it. In equation form: power (in watts) = work (in joules) / time (in seconds) P = W / t |
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Energy of Motion -- ``Kinetic Energy''
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vibrating
moving turning is energy associated with moving objects |
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Stored Energy -- ``Potential Energy''
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springs
chemical electrical gravitational is energy waiting to be released. |
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Properties of a substance which depends on the temperature:
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Volume: (in general, the volume increases with increasing temperature)
States: solid - fluid - gas Properties of materials: elasticity, electric resistance, speed of sound |
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Pressure
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Pressure is defined as force per area.
The area is measured in m2, the force in N. The unit of pressure is N / m2 P = F / A |
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Mechanical Waves
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a disturbance moving through a medium.
Source of disturbance -- vibrating object Medium to disturb -- but NO net displacement Adjacent portions of medium are connected -- to carry the disturbance Carry Energy and Momentum |
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Frequency:
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f=1/t
Unit is Hertz : [Hz] = [1/s] |
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Hooke's Law
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FS = -k * x
Force = - constant * [displacement from equilibrium] F = -k * x = m * a a = -(k/m) * x |
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fundamental frequency
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depends
on radius R of drum tension of membrane T material of membrane d |
