Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Physics 10
| Question | Answer |
|---|---|
| What are the three temperature scales and which is the SI unit? | Celsius (°C), Fahrenheit (°F), and Kelvin (K). Kelvin is the SI unit. Celsius and Fahrenheit are relative scales; Kelvin is an absolute scale starting from absolute zero. |
| How do you convert Celsius to Kelvin? | TK = TC + 273.15 |
| How do you convert Fahrenheit to Celsius? | TF = (9/5)TC + 32 |
| What is absolute zero? | The point where particles have minimum thermal motion. It is 0 K, -273.15°C, or -459.67°F. |
| What is the difference between temperature, heat, and internal energy? | Temperature = average kinetic energy of molecules. Internal energy = total kinetic + potential energy of all particles in a system. Heat = energy transferred between two objects at different temperatures in contact. |
| What is thermal equilibrium? | When two objects at different temperatures come into contact, heat transfers from the hotter to the cooler object until both reach the same temperature. |
| What are the three methods of heat transfer? | Conduction (direct contact), convection (fluid density differences), and radiation (electromagnetic waves through empty space). |
| What does a high vs. low thermal conductivity (k) value indicate? | High k = good conductor of heat. Low k = poor conductor, better heat preservation (insulator). |
| What does the Zeroth Law of Thermodynamics state? | If two thermodynamic systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other. |
| What does the First Law of Thermodynamics state, and what is its equation? | The change in internal energy equals heat added to the system minus work done by the system. ΔU = Q − W. |
| What are the sign conventions for Q and W in the First Law? | Q is positive when heat is added to the system, negative when removed. W is positive when work is done by the system, negative when done on the system. |
| What does the Second Law of Thermodynamics state? | The total entropy of a system either increases or remains constant in any spontaneous process; it never decreases. |
| What is entropy and how is it calculated? | Entropy is a measure of disorder or how much energy is unavailable to do work. ΔS = Q/T, where Q = heat transferred (J) and T = temperature (K). Units are J/K. |
| What is an isothermal process and what are its key relationships? | A process at constant temperature. ΔU = 0 and W = Q. Any heat absorbed is exactly balanced by work done by the system. |
| What is an adiabatic process and what are its key relationships? | A process with no heat exchange with surroundings. Q = 0 and ΔU = −W. All internal energy changes are due to work alone. |
| What is an isobaric process and its work formula? | A process at constant pressure. W = PΔV. Volume and temperature may change. The full First Law applies: ΔU = Q − W. |
| What is an isochoric process and its key relationship? | A process at constant volume (also called isovolumetric). W = 0, so ΔU = Q. All heat added or removed directly changes internal energy. |
| What is the difference between reversible and irreversible processes? | Irreversible processes result in a final state different from the initial state and are path-dependent. Reversible (cyclical) processes return to their original state after each cycle. |
| Why can't heat spontaneously flow from a cold object to a hot object? | Because this would decrease the entropy of the system, violating the Second Law of Thermodynamics, which requires entropy to increase or stay constant in any spontaneous process. |
| A gas is compressed rapidly in an insulated container. What happens to its temperature and why? | Temperature increases. Because the container is insulated, no heat is exchanged (Q = 0, adiabatic process). Work is done on the gas (W is negative), so by ΔU = −W, internal energy increases, raising temperature. |
| Two objects made of different materials are the same size and heated equally. Why might one expand more than the other? | Because thermal expansion depends on the coefficient of linear expansion (α), which is an intrinsic property of each material. The material with the higher α will expand more for the same temperature change. |
| In an isothermal expansion of an ideal gas, the internal energy doesn't change — so where does the energy for the work done come from? | It comes entirely from the heat absorbed from the surroundings. Since ΔU = 0, the First Law gives W = Q, meaning all heat input is converted directly into work. |
| Why is temperature measured in Kelvin (not Celsius) when calculating average kinetic energy or entropy? | Because K is an absolute scale starting at absolute zero. C values can be negative and don't reflect the actual energy of particles. K ensures the proportional relationship between temperature and KE (Kavg = 3/2 KBT) and S (ΔS = Q/T) remains meaningful. |
| What is the relationship between volume change and work in a thermodynamic process? | When a gas expands (+ΔV), the gas does work on its surroundings — work done by the system is positive. When a gas is compressed ( −ΔV), work is done on the gas by surroundings — work is negative. This is captured by W = PΔV (valid for isobaric processes). |
Created by:
smurtab