Flashcards
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Flashcards do conjunto (86)
- 1Who developed the first practical steam engine?Thomas Savery
- 2How did Hero's steam engine work?The steam produced in the kettle generates mechanical motion,causing the ball to spin.
- 3How did Thomas Savery's steam engine work?First of all, the receiver gets completely filled with steam. When the connection to the boiler is closed and the receiver has already cooled down, a negative pressure occurs, which sucks water into the receiver as long as the valve (1) is opened. Now, valve(1) closes and valve (2) opens. The pressure of the steam of the boiler presses the water through the open valve 3 upward.
- 4Who improved Savery's design and how?James Watt used cold water
in his engine to allow the steam
to condense faster. - 5How did Watt adapt his steam engine, and how did this help during the Industrial Revolution?Watt added a system of gears and levers so that a piston could turn a wheel, used in textile factories.
- 6Watt's steam engine adapted to drive many types of machinery?Steam powered tractors,Trains, and paddle-wheel steamboats
- 7What are steam turbines used for?They power great ocean liners and cruise ships
- 8Steam turbines don't use pistons, what do they use?Steam passes through curved blades, and steam hits axle which turns. The shape is usually cone like
- 9What did Thomas savery's engine draw from coal mines?Water form coal mines
- 10Who proposed that matter was made from air, fire and water?Greek philosopher Embedcles
- 11What is the Phlogiston theory of heat?That some type of invisible fluid flowed out, when things were burned.
- 12What was the Caloric theory of heat?proposed that heat-or caloric was a massless fluid that moved from hotter to cooler objects.
- 13Why were scientists confused about the phlogiston theory?Because if phlogiston is a massless fluid that flows out, how come when magnesium is burned, the ashes have a greater mass
- 14Who proposed a modern theory of heat?Benjamin Thompson (Count Rumford)
- 15What was Count Rumford's hypothesis?Heat is equal to energy. He states that mechanical energy can be converted into heat. No such thing as caloric.
- 16What led Count Rumford to his theory>His tools would get hot when he drilled a hole into a cannon. He said that caloric is suppose to flow from warmer to cooler, but there were no hot objects to start with.
- 17What is the Law of Conservation of energy?energy cannot be created or destroyed, but can be transferred into different forms.
- 18Calorie?amount of energy added to 1.0 g of water to increase its temp. by 1.0 degrees Celsius.
- 19What is kinetic energy?energy associated with movement
- 20Kinetic-Molecular Theory?molecules of a gas are in constant/random motion
- 21Random motion can be referred to as?Brownian motion
- 22Heat is the...transfer of thermal energy
- 23Heat and work are mechanisms? how?energy can be transferred from one object to another.
- 24Amount of energy need to raise the temp of 1.0 g of a substance by 1.0 degree CelcuisSpecific Heat capacity
- 25Less amount of a substance but at the same temp meansless kinetic energy, because there are less particles to interact with.
- 26Temperature?average of all kinetic energies of all particles in a substance
- 27Heat?Sum of all kinetic energies of all the particles in an object
- 28Who found the mechanical equivalent to heat?Joule
- 29What is the unit of energy called today?Heat
- 30field of physics that deals with forces/motions involved in heatThermodynamics
- 311st Law of Thermodynamics?energy cannot be created or destroyed, can be transferred.
- 32Energy can be increased by Energy can be decreased by-adding heat/performing work
-heat flowing out/work done by system - 332nd Law of ThermodynamicsNo energy conversion is 100% efficient, some energy will always stay in the form of thermal energy.
- 341st law of thermdynamics also incudes mass why?Because mass can be converted into energy. So matter is a form of energy.
- 35What is work and its formula?Work is the transfer of mechanical energy. W= F x D
Force x Distance
F= newtons
D= metres
W= joules - 36How do you find work on graph? Geometric Shapes?Triangle=bxh/2
Square/rectangle=lxw
Circle: pi r square
semicircle: pi r squared/2 - 37How to find work on a graph? Non-uniform shapes?-determine force/width of one square (1cm square)
-determine work of one square
-count how many squares are in the shape
-multiply work by # of squares
this gives you total work - 38Joules method for determining mechanical equivalent of heat?Joule used an apparatus
- 39slope?rise/run= y2-y1/x2 - x1
- 40The power of steam, in modern tech is used to driveturbines
- 41Steam engines burn fuel/heat and water outside of the engines then inject inside. Internal combustion?occurs inside cars,vehicles,and trucks
- 42How is internal combustion different from the steam engine?-fuel goes directly to cylinder
-less fuel/water used - 43what type of engine powers trucks,cars and buses?Internal Combustion
- 44What type of piston is found in vehicles?Four-cycle piston
- 45What are 4 methods of generating electricity?-Fossil Fuels
-Nuclear
-Hydro-electric
-wind powered - 46Motion can be scalar or vector Scalar?describes the magnitude of motion (size and amount) DO NOT describe direction of motion.
- 47What is distance? Is it scalar or vector?Distance is the length travelled by two objects between two points. Distance is in metres.
- 48What is a vector quantity?Describes both the magnitude and direction of motion. Vector rely on position and are described as displacement
- 49What is position? What is displacement?-describes distance and direction in metres
-straight line between two points in metres with arrows on top of d
-formula d2-d1 - 50Calculating displacement?Tip to tail method.
up=north +
down= south -
right=east +
left=west - - 51Uniform motion?Motion of an object which is constant throughout
- 52Scalar Uniform motionUniform motion that describes magnitude but NOT DIRECTION
- 53Scalar motion is known as speed? What is speed and its formula?Speed: how far an object travels in a given amount of time
v=d/t
velocity=distance/time
v=m/s distance=m time=s - 54Vector Uniform Motion?describes the magnitude and distance of object
- 55Vector uniform motion is known as velocity What is velocity/formula-change in magnitude/direction in a given amount of time
- v=d/t with arrow above v
- or v= df-di/tf-ti - 56Total displacement= displacement from matt to nate=-d1+ d2t
- dn-dm= displacement from matt to nate - 57Steep Slope= motion Flatter Slope = motion-Faster
-Slower - 58Distance vs Time graph can be changed into what kind of graph? How?Speed vs Time Graph
You would calculate slope of Distance vs Time Graph - 59If you calculate the slope of a displacement vs time graph you get?Velocity vs Time graph
- 60How do you find displacement on a velocity vs time graph?You calculate the area under the graph.
- 61What is non-uniform motion? What is acceleration?- motion that changes over time
- change of velocity over time - 62Formula for acceleration? Acceleration of gravity?A= V/t or A= vf-vi/tf-ti
- 9.81m/s squared - 63Gravity is stronger under our oceans and WEAKERon top of mountains
- 64How do you go from Displacement graph to acceleration graph?Displacement vs. Time Graph Velocity vs. Time Graph Acceleration vs. Time Graph
Slope (rise/run or y2 – y1/x2 – x1) - 65How do you from acceleration graph to displacement graph?Acceleration vs. Time Graph Velocity vs. Time Graph Displacement vs. Time Graph
Area ( Rectangle = l x w , Triangle = 1/2bh) - 66Force/formula?-push/pull on object
-F=ma
F=newtons m=kg a-acceleration m/s square - 67Newtons First Law- an object in motion will stay in motion unless acted upon by an outside force
-an object in rest will stay in rest unless acted upon by an outside force - 68Newton's Second Law (discover force formula)-when force is exerted on an object, it will either speed up or slow down
- 69Newton's Third Law:For every action there is an opposite or equal reaction.
- 70As force increases what happens to acceleration As mass increases what happens to force-increases
- 71If you have to objects with the same force applied, but different masses, which one has greater accel?the one with less mass has greater accel.
- 72Potential energy:-energy due to objects position-stored energy
- 73Elastic Potential energy?-an object elastic if it has the ability to return to its original shape
- 74Chemical Potential Energy:-energy in chemical bonds
- 75Nuclear potential energy:- nuclei that have the potential to split-fission-
- 76Gravitational potential energyPotential energy due to position above ground
- 77formula for potential energy?Ep=mgh
ep=potential
m=mass kg
g= accel of gravity
h= height m - 78Work also equalsW=Ep
W=mgh - 79What type of energy occurs when you release stored potential energy/formula-Kinetic
-Ek=mv2/2
ek in joules - 80Formula for Law of conservation of energyEp=Ek
mgh=mv2/2 - 81Efficiency formula:efficiency=useful output energy/input energy x 100%
- 82Explain energy transformation of car -effieciencyChemical energy is stored in gasoline which is transferred to mechanical.
-20% - 83Fluorescent light bulb or incandescent light bulb?Fluores. are much more efficient.
95% of thermal energy is lost in incandes. - 84What energy transformation occurs in electric motors?Electric to mechanical
- 85What is cogenerationUsng waste heat from thermo-electric generators to generate heat ffor buildings
-80% efficient - 86Deep lake water coolingpurpose/function to cool downtown toronto buildings by pumping up cool water from lake ontario in ac vents
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- FlashCards sobre Sem título, criado por jassparmar98 em 19-01-2014.
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