Hot Hot Hot
A cold soda can is placed on a warm oven. Which direction does thermal energy flow?
From the warm oven to the cold soda can.
Name at least 2 things that affect the amount of thermal energy in an object.
Temperature, mass, material, state of matter
What is the word for the average value of the kinetic energy of the particles in an object.
Temperature
How many ways can thermal energy by transferred? And what are they?
3-Conduction, Convection, and Radiation
In science, what is heat?
Energy transferred between objects at different temperatures.
When an object is hot, how do it's particles move?
fast
If you have 2 copper blocks that are at the same temperature, what could make them have different amounts of thermal energy?
One could be bigger. The mass could make them different.
Which object's particles have the greater average kinetic energy: water at 25o C or water at 60o C?
The water at 60o C
A metal spoon becomes hot while sitting in a bowl of soup.
Conduction
What happens to the particles of an object when its temperature increases?
Their average kinetic energy increases, so they move or vibrate faster.
You hold an ice cube in your hand. Which object gains thermal energy?
The ice cube.
Two objects have the same mass and temperature, but are made out of different materials. Can they contain different amounts of thermal energy?
A bathtub and a coffee cup both contain water at 40o C. Which has more thermal energy and why?
The bathtub, becuase it contains more water and therefore more particles.
You feel the warmth of a campfire even though you are not touching it.
Radiation
What is the name for the condition in which two objects have reached the same temperature and there is no net energy transfer between them?
Thermal equilibrium.
How are mass and thermal energy related?
If there is a change in mass, then there is also a change in thermal energy. If one increases, the other increases. The bigger the object, the more thermal energy it has.
You place equally hot samples of steel, ceramic, and rubber into identical cups of cold water. Why miht the water in each cup warm by a different amount?
Different materials store and release different amounts of thermal energy.
Put these objects in order from least thermal energy to most: a wooden spoon at 40o C, a toothpick at 40o C, and a wooden table at 30o C.
1- toothpick, 2- spoon, 3- table
In cold climates, the heater is on the floor so the heat fills up the whole room.
Convection
A student holds one hand above a hot pan and the other hand beside it. Which type of transfer is most important above the pan, and which can be felt beside it?
Convection is most important above the pan, and radiation can be felt beside it.
A cup of coffee at 70o C is placed in a room that is 22o C. Predict the coffee's final temperature if it remains there long enough and explain why.
It will cool to 22o C because energy flows from hot to cold until they reach the same temperature.
An engineer wants a wall to absorb energy during the dy and release it at night. Give 2 properties the engineer should investigate.
The wall's material, the wall's mass, the wall's thickness, temperature change, or ability to absorb, store, and release thermal energy.
Two objects have the same amount of thermal energy. Must they have teh same temperature? Explain.
No. Their mass, material, or state could be different, so they can have the same thermal energy but different temperatures.
A pot of water is heated on a stove. Identify one example of conduction and one example of convection
Conduction- energy moves from the stove to the pot and from the pot to the water inside.
Convection- inside the pot, warm water rises and cooler water sinks.
A bowl of soup begins at 80°C in a 20°C room. Describe what happens to the soup’s particles and energy as it reaches thermal equilibrium.
The soup transfers energy to the cooler surroundings. Its particles lose kinetic energy and move more slowly, so its temperature decreases until the soup reaches about 20°C.