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90 Cards in this Set
- Front
- Back
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What is the unifying equation for force?
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Force= Mass x Acceleration
F=MA |
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What is a force?
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A force is a push or pull that causes change in shape
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What is mass?
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total amount of matter in an object
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What are the units for mass?
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SI - grams
English - pound-mass |
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What is weight?
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measurement of gravity time mass
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What is gravity in SI units?
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9.8 m/s²
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What is torque?
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force-like quantity in rotational mechanical systems
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What is torque measured in?
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SI - Nm
English - lb*ft |
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When forces act in the same direction, the ____ ______ is the sum of the 2 forces
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net force
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When opposing forces are equal, they are said to be in a state of ________
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equillibrium
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What are prime movers?
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force-like quantities in mechanical systems
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What is the prime mover for thermal systems?
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Temperature differences
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Density is found by dividing...
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mass by volume
M/V |
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The density of a substance divided by the density of water is known as...
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specific gravity
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What measures density or specific gravity of liquids?
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hydrometer
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______ is measured by dividing a unit of force by a unit of area.
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Pressure
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What is the english unit for pressure?
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psi
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What device is used to measure pressure differences?
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manometers
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The two types of fluid systems are...
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Hydraulic & Pneumatic
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What fluid does a hydraulic system use?
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liquids
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_____ are compressible.
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gasses
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______ are not compressible
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liquids
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Pressure increases with ______
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depth
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______ ______ is measured from a zero pressure
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absolute pressure
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What is atmospheric pressure in psi?
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14.7 psi
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What is the weight density of water?
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62.4 lbs/ft^3
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Voltage comes in what two forms?
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AC & DC
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What is the most common form of DC current?
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Batteries
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The alternating of AC current is measured in ______
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hertz
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The alternating of AC current is known as ________
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frequency
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__________ measure voltage difference
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Voltmeters
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Multimeter measure voltage, ______, and __________ (in ohms)
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amperage
resistance |
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The positive pole in a battery is the ______
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anode
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The negative pole in a battery is the ______
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cathode
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What are the 4 basic items in a simple electrical circuit?
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1. source (power supply)
2. conductors (wires) 3. load (what is powered) 4. control element (switch) |
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What is the prime mover in thermal systems?
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Temperature difference
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_______ is the measure of the average energy of motion of molecules in a substance.
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Temperature
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________ use three wires of two different metals to measure temperature
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Thermocouples
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Where is the degree symbol normally placed.
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Before the unit (°F)
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Where is the degree symbol placed when giving a temperature difference
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After the unit (F°)
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In the equation for work, force is a _______ and distance is a _______
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force-like quantity
displacement-like quantity |
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________ work is the work going into a system
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input
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_________ work is work the system does
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output
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__________ =Output work/Input work x 100% and the total cannot exceed 100%
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efficiency
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Spring scale measure input and _______ output force
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output
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In rotational mechanical systems...
angle of movement is symbolized by ________ |
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What is the basic english unit for work?
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foot-pounds (ft*lb)
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The basic SI unit for work is what?
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Newton-meter (Nm)
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1 Nm = 1 _____
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joule
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__________ __________ _____ is performed when work is done in a straight line
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linear mechanical work
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_________ ____________ ____ is work done around an axis or a rotation
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Angular rotational work
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Mechanical work causes an object to start moving, _____ ______, or change ________
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stop
moving direction |
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What is the equation for fluid work?
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W=∆p*V.
pressure difference * volume |
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The formula for fluid work can also be expressed as...
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W=p*∆V
pressure * volume difference |
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when the given height for a fluid is raised, you must also know the ____ ______ of the fluid to calculate fluid work
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weight density
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In a _____ fluid system the fluid is reused
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closed
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There is no such thing as _______ or ________ fluid work
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angular
linear |
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The cross-sectional area of a cylinder can be found by multiplying __________ by the diameter²
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0.7854
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a ______ is a quantity of charge that is = 6.25*10^18 electrons
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coulomb
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What symbol is used in an equation for a coulomb
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q
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Electrical charge can be calculated by multiplying amps by time. What unit cancels
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time
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What is the basic unit for electrical work
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joule
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Input work is performed by an electric pump or motor will be given in _______
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joules
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a rate is a displacement-like quantity divide by an ______ ____
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elapsed time
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Velocity is a ________ that is the measure of linear mechanical _______
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vector (amount and direction)
rate |
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______ is similar to velocity
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speed
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Units for linear mechanical rate are ___/____ (english) or ____/____ (SI)
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ft/sec
m/sec |
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Angular rate is expressed in ____/____ (SI) or _____/____ (english)
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rad/sec
rev/min |
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6.28 rads = one ______
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revolution
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Acceleration is the rate at which speed ________ or __________
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increases or decreases
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Flow rate is the volume of fluid moved in a given period of ____
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time
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Units of fluid flow are
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gallons/min
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_________ is the quality of a substance related to its thickness; it can be reduced be heating up
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viscosity
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Under the same pressure, a larger pipe will have a ______ flow rate than a smaller pipe
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higher
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____________ rate is the amount of charge moved in a given amount of time
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electrical rate`
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current is symbolized (in equations) by
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I
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a milliampere =
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1/1000 amps
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a microampere =
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1*10^ -6
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an ammeter is used to measure
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current
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________ measure frequency of alternating current
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Hertz
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an _________ can measure frequency as well as voltage
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oscilloscope
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Heat flow rate is symbolized by
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Qh
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Units of heat include:
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English : BTU's
SI : calorie |
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________ ________ is used to contain/store heat energy
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dewar flask
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a ______________ thermometer can be used to measure heat flow rate
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thermocouple
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What is the unifying equation for resistance
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Force
_____ Rate |
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The 2 forms of resistance in mechanical system are
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friction and drag
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Equation of force of friction is
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Force times coefficent of friction
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_________ friction must be overcome to start an object in motion
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sliding
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_________ friction must be overcome to keep an object in motion
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kinetic
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