qfocus. qfocus pt 2 qfocus pt 3 you can design, build, and refine a device that works to convert one...
TRANSCRIPT
![Page 1: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/1.jpg)
QFocus
![Page 2: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/2.jpg)
QFocus pt 2
![Page 3: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/3.jpg)
QFocus pt 3•You can design, build, and
refine a device that works to convert one form of energy into another form of energy
![Page 4: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/4.jpg)
• Label questions as open or close ended questions
• Change three from open ended to close ended or vise versa.
![Page 5: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/5.jpg)
•Pick 3 questions that you want to be answered by the time you are able to build and explain this device.
![Page 6: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/6.jpg)
•Choose 2 questions to share with the class.•Why did you choose
these 2 questions?
![Page 7: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/7.jpg)
Energy and Work
![Page 8: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/8.jpg)
Energy
• in the next 3 minutes, think and discuss as many examples of energy and types of energy you can think of.
![Page 9: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/9.jpg)
Types of energy
• Electrical Energy
• Chemical Energy
• Thermal Energy
• Mechanical Energy
![Page 10: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/10.jpg)
• There are many different types of energy in the world.
• Each of these can be transferred and transformed into other types of energy for different uses.
![Page 11: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/11.jpg)
Ex. Nuclear Power Plant
![Page 12: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/12.jpg)
• In the next 3 minutes, discuss with your group and write down all the ways money exists in the world, how it is stored and used.
![Page 13: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/13.jpg)
“Money as energy” model
• Cash or debit card = kinetic energy– Energy due to motion. Kind of like cash, is readily
usable.• Bank/savings account = potential energy– energy stored because of where the mass is
located, e.g. gravitational potential energy or magnetic potential energy. Like savings, it is there, but must be transferred in order to be used.
• Getting a paycheck or making payments = Work
![Page 14: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/14.jpg)
WORK• SCIENTIFIC WORK—energy transferred by
applying a force on an object over a certain displacement. Work, like energy, is measured in Joules
W = F Δx
1 joule = 1 Nm = 1 kg m2 / s2
![Page 15: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/15.jpg)
Work (cont.)• Energy can be transferred into an object (+
work)
• or energy can be transferred from an object (- work)
![Page 16: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/16.jpg)
Back to energy
• Since work is the flow of energy, you can define energy as:–Energy is the ability to do work.
![Page 17: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/17.jpg)
Dropping a golf ball• What is doing work on the golf ball as it is
lifted up? How is the work being done?• What is doing the work as the golf ball is
falling down? How is the work being done?• What does the golf ball do to the pin
when it hits it? Use physics vocabulary.• What happens to the amount of energy
the golfball has when you change the height you drop it at? How do you know?
![Page 18: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/18.jpg)
Potential Energy
• It is the amount of energy stored based on the location of the object.
• It is equal to the amount of work that it takes to place the object in that location.
![Page 19: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/19.jpg)
Discuss with your group
• Can we use potential energy to do work? [provide evidence and reasoning]
• [you can look back at your notes for help, or think about the demonstration we just did]
![Page 20: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/20.jpg)
Gravitational Potential Energy
• The energy stored due to the height of an object
• PEg = mgh
m = mass, g = acceleration due to gravityh = height
![Page 21: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/21.jpg)
![Page 22: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/22.jpg)
Defining the height
• When we talk about PE, we use the difference in PE from one position to another.
• For gravitational PE, we need to define a position we will consider to be zero height
![Page 23: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/23.jpg)
Ex.
• A 50 kg person is on a balcony 4 m above the ground. Then the person goes up on the roof of the building, which is 10 m above the ground. What is the person’s gravitational potential energy relative to the balcony?
![Page 24: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/24.jpg)
Elastic Potential Energy
• Based on how much you stretch or compress and elastic object (rubber band, spring, bungee cords, etc.)
• Again, there will be some zero position where the elastic object will be neither stretched or compressed (in equilibrium).
![Page 25: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/25.jpg)
example of a spring
![Page 26: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/26.jpg)
Kinetic Energy
• Kinetic energy is the energy due to the motion of the object.
![Page 27: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/27.jpg)
The equation for Kinetic Energy is:
KE = (1/2) m * v 2
m = mass, v = velocity
![Page 28: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/28.jpg)
Power
![Page 29: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/29.jpg)
• Work does not take into account the time it takes to cause a displacement by applying a force.
• The work can be done quickly or slowly, and you will get the same amount of work done.
![Page 30: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/30.jpg)
Power
• Power is the rate at which the work is done.
• P = work / time
• Units = J/s = Watts = W
![Page 31: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/31.jpg)
Horsepower
•Horsepower is another unit for power
•1 hp = about 750 Watts
![Page 32: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/32.jpg)
kiloWatt hour• Energy companies use the unit kW
hour to define a unit of energy.
• They use this energy to calculate your energy bill
• 1 kW hr = [1 kW] x [1 hr] = [1 kW] x [3600 s] = [1 kJ/s] x [3600 s] = 3600 kJ
![Page 33: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/33.jpg)
Work and Kinetic Energy
• How can you make an object speed up?
• What happens to the energy of an object when it speeds up or slows down?
![Page 34: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/34.jpg)
Work - Kinetic Energy Theorem
• The work you put into, or the work an object does will change the kinetic energy of the object:
• W = ΔKE = KEf – KEi = (1/2)mvf2 –
(1/2)mvi2
![Page 35: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/35.jpg)
Ex 1
• A 500 kg car is moving at 2 m/s. If a tow truck pulls the car and does 1000 J of work, what is the new velocity of the car?
![Page 36: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/36.jpg)
Temperature, Heat, and Internal Energy
![Page 37: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/37.jpg)
Thermal Energy
• Thermal energy is energy possessed by an object or system due to the movement of particles within the object or the system.
![Page 38: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/38.jpg)
Temperature
• Temperature - measure of the average molecular kinetic energy of a substance
• Heat - transfer of energy due to difference of temperature– Objects do not contain heat– Flows from higher to lower temperature objects
![Page 39: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/39.jpg)
![Page 40: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/40.jpg)
Thermal Equilibrium
• Thermal Equilibrium - objects in thermal contact reach the same temperature
![Page 41: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/41.jpg)
Internal Energy
• Total of all energies inside a substance or system– Kinetic– Potential
• A substance does not contain heat, but contains energy.
![Page 42: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/42.jpg)
Discuss, decide, and provide evidence and reasoning
• Compared to a giant iceberg, a hot cup of tea has
• (A) more internal energy and higher temperatures(B) higher temperature but less internal energy(C) a greater specific heat and more internal energy(D) none of the above
![Page 43: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/43.jpg)
• Temperature is a measure of an object's• (A) average molecular kinetic energy
(B) average molecular potential energy (C) total molecular kinetic energy(D) total molecular potential energy
![Page 44: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/44.jpg)
• Heat flows from an object with a high• (A) internal energy to an object
with a lower internal energy(B) temperature to an object at a lower temperature(C) both of the above since the two phrases are equivalent
![Page 45: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/45.jpg)
• If only the potential energy of the molecules in a body is increased, the absolute temperature of the substance• (A) increases
(B) decreases(C) remains the same
![Page 46: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/46.jpg)
•Could the thermal energy of a bowl of hot water equal that of a bowl of cold water?
![Page 47: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/47.jpg)
Different types of systems• There are three different types of systems we
can define:1. Open system: In this system, matter and
energy can flow freely in and out of the system.
2. Closed system: Here, only energy can flow freely in and out, but the matter will stay inside the system.
3. Isolated system: For this, both the matter and energy stay inside the system and cannot flow freely in or out.
![Page 48: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/48.jpg)
![Page 49: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/49.jpg)
What type of system is this? Why?
![Page 50: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/50.jpg)
What type of system is this? Why?
![Page 51: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/51.jpg)
The Law of conservation of energy
![Page 52: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/52.jpg)
Law of conservation of energy
• In an isolated system, the total amount of energy remains the same.
• That means:
Etotal initial = Etotal final
![Page 53: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/53.jpg)
![Page 54: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/54.jpg)
![Page 55: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/55.jpg)
For mechanical energy
• mechanical energy only involves KE and PE, so from the law of conservation of energy:
KEinitial + PEinitial = KEfinal + PEfinal
![Page 56: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/56.jpg)
• If I drop the mass from a pendulum, will my face be safe? Why?
![Page 57: QFocus. QFocus pt 2 QFocus pt 3 You can design, build, and refine a device that works to convert one form of energy into another form of energy](https://reader030.vdocuments.mx/reader030/viewer/2022012913/56649da75503460f94a92952/html5/thumbnails/57.jpg)