th 1 Give two examples of heat convection 2 Describe specific heat in your own words 3 Which of the following substances heats up the quickest Aluminum 900 cJ kg K Copper 390 cJ kg K ID: 755925
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Catalyst – Tuesday 18th
1. Give two examples of heat convection.2. Describe specific heat in your own words.3. Which of the following substances heats up the quickest? Aluminum = 900 c/J kg K Copper = 390 c/J kg K Iron = 470 c/J kg K 4. Do you remember the law of conservation of energy? Define it in your own words!
Essential Questions: How are temperature and energy related? Where does energy come from and where does it go? How is energy converted into different forms?Slide2
Catalyst – Tuesday 18th
1. Give two examples of heat convection. Heating system, creamer swirling in coffeeDescribe specific heat in your own words.Energy needed to change temperature.3. Which of the following substances heats up the quickest? Aluminum = 900 c/J kg K Copper = 390 c/J kg K
Iron = 470 c/J kg K 4. Do you remember the law of conservation of energy? Define it in your own words!
Yes, it is when matter cannot be created nor destroyed but ONLY change form!
Essential Questions: How are temperature and energy related? Where does energy come from and where does it go? How is energy converted into different forms?Slide3
Agenda (10) Catalyst & Answers)
(5) Blocks 3&4 Heat transfer rap video(10) Specific Heat worksheet(40) Gallery Notes on KE & PE(20) Teacher Lecture(5) Exit ticketSlide4
Catalyst – Tuesday 19th
1. What is the formula for Work? 2. What is the formula for Power? 3. If substance A has a specific heat of 5J/C and substance B has a specific heat of 1 J/C, which one will heat up quicker? 4. I do 20J of work on a box and move it 5m, what force did I apply to the box? Essential Questions: How are temperature and energy related? Where does energy come from and where does it go? How is energy converted into different forms?Slide5
Unit 8 - Energy
HeatTemperatureThermal EnergyWork
PowerKinetic EnergyPotential EnergySlide6
Law of Conservation of Energy
Energy is neither created nor destroyed, it can only change form. Example: A flashlight - The energy from the battery is converted into light energy. Slide7
Kinetic Energy
Kinetic Energy is the energy of motion
Write 3 examples of something that would have HIGH Kinetic
energy.
1. Running
2. Roller Coaster
3. High speed trainSlide8
Things like: Slide9
Kinetic Energy Formula
Kinetic Energy Formula = ½ (mass x velocity2)KE (J) = ½ m (kg) x v2 (m/s)
1. Calculate the kinetic energy of a running back that has a mass of 80 kg and is running at a velocity of 8 m/s.
KE=2,560 JSlide10
Which has more Kinetic Energy???
1. A bus full of passengers travelling at 25 mph OR an empty bus at 25 mph2. A toy car moving at 4 m/s OR a toy car sitting at rest on a shelf3. 7kg bowling ball moving down the alley, 7kg bowling ball at rest.4. An adult riding a bicycle, a teenager driving a car.Slide11
Gravitational Potential Energy
Gravitational potential energy is the stored energy of an object as a result of it’s position/height .Higher up =
more Potential Energy
Write 3 examples of something that would have HIGH
POTENTIAL
energy
1)Basketball player in the air dunking
2)Air plane in the sky
3)Football in the air Slide12
Things like: Slide13
Gravitational Potential Energy Formula
PEgravitational = mass (kg) x gravity (Ag) x height (m)
2. John has an object suspended in the air. It has a mass of 50 kilograms and is 50 meters above the ground. Find its gravitational potential energy.PEgravitational = 24,500JSlide14
Which has more Potential Energy???
1. An empty box sitting on a shelf OR a full box sitting on the same shelf2. A 10kg cat at the top of a flight of stairs OR a 3 kg kitten at the top of the stairs 3. A pitcher throwing a baseball OR a softball on the ground.4. Roller coaster cart on top of the coast OR cart at the bottom of the coaster?Slide15
Mechanical Energy
Mechanical Energy = Kinetic Energy +Potential Energy
Where does the roller coaster have the most Potential Energy? WWhere does the roller coaster have the most Kinetic Energy?
X
Where does the roller coaster have the most Mechanical Energy?
W, X, Y,ZSlide16
Mechanical
Energy....What??!? Energy goes through a series of transformation and changes. So potential energy turns into kinetic energy and
turning back into potential energy. A small quantity of this energy is transferred as heat to the wheels and as vibrations that produce a roaring sound in the air. In a mechanical system such as a roller coater or a swinging pendulum,
the energy
in the system at any time can be calculated by
adding
the kinetic and potential energy to get the total mechanical energy. The law of conservation of energy requires that at any given time, total energy should be the same.Slide17
Friction and Mechanical Energy
Why doesn’t a roller coaster go on forever? Reasons below…..Energy is used for other things. Roller coasters produce
heat , the track heats up, etc.
Friction is a force that
uses
some of the mechanical energy in a system.Slide18
Conceptual
UnderstandingA penny is dropped off the Eiffel tower. As it falls, what happens to it’s potential energy? What happens to it’s kinetic energy?As it falls, it’s velocity increases so …..
However, it loses height so ….
Mechanical energy stays the same
in the air because
….. Slide19
Kinetic or Potential?
1. A car is driving down the highway at 65 mph2. A car is parking at the top of a hill 3. a rubber band zinged from your finger4. moving a skateboard5. A glass of milkSlide20
Kinetic & Potential Energy Questions
1. What is the potential energy of a 2-kilogram potted plant that is 1 meter-high plant stand? PEgravitational = mgh PEgravitational = (2kg)(9.8m/s2)(1m)PEgravitational = 19.6J2. What is the kinetic energy of a 3-kilogram ball that is rolling at 2 meters per second? KE = ½ mv2KE = ½(3kg)(2m/s2)KE = 6 JSlide21
For the Final…..
Answer:?Slide22
For the Final….
Answer:?Slide23
ET - Kinetic/Potential Energy 3.1.2
1. What is kinetic energy? 2. Object A is sitting 100m above the ground, Object B is sitting 10m above the ground. They are the same size, which has more potential energy? 3. Calculate the kinetic energy of a 3 kg car moving 6 km/s4. Calculate the potential energy of a box that is sitting 2 m above the ground and has a mass of 2kg 5. Why does a roller coaster lose some energy while running on the tracks? Where does that energy go? Slide24
ET – Wednesday 19th
When a rock is dropped from a height of one meter, the graviational potential energy of the rock is converted to kinetic energy. When the rock hits the floor and does not bounce, what happends to the kinetic energy of the rock?When one form of energy is converted into other forms of energy, what happens to the total amount of energy?