Temperature
Imagine you have a glass of iced tea and a cup of hot coffee sitting on a table in a room at a comfortable room temperature. Describe what happens to the temperature of each drink over time and why.
A glass of iced tea will gradually warm up to the room temperature, while a cup of hot coffee will cool down to the same room temperature. This is because heat flows from objects of higher temperature to objects of lower temperature, eventually reaching thermal equilibrium
Describe the three main ways heat can be transferred: conduction, convection, and radiation.
Conduction involves heat transfer through direct contact, convection involves heat transfer through the movement of fluids, and radiation involves heat transfer through electromagnetic waves.
Describe the process of conduction
Conduction is the transfer of energy, typically heat or electricity, through direct physical contact
What does a high specific heat capacity tell you about how easily a substance's temperature will change when heat is added or removed?
A high specific heat capacity tells you that a substance's temperature will change relatively slowly when heat is added or removed.
True or False
Heat is Hot
True
If the average kinetic energy of the molecules in a gas increases, what happens to the temperature of the gas?
The temperature of the gas also increases.
Explain the difference between heat and internal energy. Can an object have a high internal energy but low heat?
Internal energy is the total energy contained within a system because of the motion and its molecules, while heat is the transfer of energy between two systems due to a difference in temperature. Internal energy is a property of the system, whereas heat is a process that changes the internal energy. Yes, an object can have high internal energy but low heat if the internal energy is not being actively transferred to another object
Describe the process of convection
Convection is a heat transfer process driven by the movement of fluids, like air or water
If you have two identical mugs, one filled with hot coffee and the other with hot chocolate (assuming they have slightly different specific heat capacities), and they lose heat to the surroundings at the same rate, which drink will cool down faster?
The drink with the lower specific heat capacity will cool down faster.
True Or False?
Temperature is measured in grams?
False
Why do different materials, like metal and wood, feel like they have different temperatures even when they have been in the same room for a long time?
They feel different to the touch because of their different thermal conductivities.
Why does rubbing your hands together make them feel warmer? What is happening at a molecular level to cause this temperature increase?
The rubbing action increases the movement and vibration of atoms and molecules within the skin
What is thermal radiation?
Thermal radiation is the emission of electromagnetic waves from all matter that has a temperature above absolute zero
Why does water have a relatively high specific heat capacity compared to many metals? What are some practical implications of this property of water?
Water's relatively high specific heat capacity compared to many metals arises primarily from its intermolecular forces, specifically hydrogen bonds
True Or False?
Heat can change an objects phase
True
If you leave a bottle of water in a refrigerator, what happens to its temperature over time?
Its temperature will decrease over time until it reaches the same temperature as the refrigerator itself
If you hold an ice cube in your hand, is heat flowing into the ice cube or out of the ice cube?
Heat is flowing into the ice cube
If you hold a metal spoon with one end in a hot bowl of soup, what heat transfer mechanism is primarily responsible for the other end of the spoon becoming hot?
Conduction
Two objects made of different materials but with the same mass are heated with the same amount of energy. If one object experiences a larger temperature change than the other, what can you conclude about their specific heat capacities?
You can conclude that the object with the larger temperature change has a lower specific heat capacity.
True or False?
Conduction is the primary way heat travels through fluids
False, convection is the primary way
What are the 3 main temperature scales?
Celsius, Fahrenheit, and Kelvin
Imagine you're stirring a pot of soup on the stove. Where is the heat energy coming from, and how is that energy being transferred to the soup? Describe the different methods of heat transfer involved.
The heat energy for the soup on the stove typically comes from the burner itself, it transfers from conduction in which the stove would be powered by electricity or gas.
A hot cup of coffee is placed on a table in a room at a cooler temperature. Describe all three mechanisms of heat transfer that are occurring as the coffee cools down.
Conduction, Convection, and Radiation
A 50 g metal block requires 235 J of heat to raise its temperature by 5°C. What is the heat capacity of the metal block? What is the specific heat capacity of the metal?
940 J/kg·°C.
True or False
Heat engines can convert 100% of the input heat into mechanical work.
False