Chapter 2 - Energy & The First Law of Thermodynamics

<p>$DKE = KE2 - KE1$ (D)</p> Signup and view all the answers

<p>The system's position within a gravitational field (D)</p> Signup and view all the answers

<p>Potential energy change (A)</p> Signup and view all the answers

<p>The ratio of useful work output to heat input (A)</p> Signup and view all the answers

<p>Work transfers energy into or out of the system. (A)</p> Signup and view all the answers

<p>Heat transfer to the hot body (B)</p> Signup and view all the answers

<p>Wcycle = Qout - Qin (A)</p> Signup and view all the answers

<p>g = Qout / Wcycle (B)</p> Signup and view all the answers

<p>300 kJ (A)</p> Signup and view all the answers

<p>3.0 (B)</p> Signup and view all the answers

<p>The change in gravitational potential energy of a mass (B)</p> Signup and view all the answers

<p>The total internal energy of the system (C)</p> Signup and view all the answers

<p>The change in energy is calculated using the equation $\Delta E = \Delta U + \Delta KE + \Delta PE$ (C)</p> Signup and view all the answers

<p>Consulting tables found in appendices of textbooks (C)</p> Signup and view all the answers

<p>Work depends on the interactions between the system and surroundings (D)</p> Signup and view all the answers

<p>The energy content change between two states (D)</p> Signup and view all the answers

<p>It is proportional to the mass of the system (D)</p> Signup and view all the answers

<p>Change in internal energy (A)</p> Signup and view all the answers

<p>Work and heat (C)</p> Signup and view all the answers

<p>Positive and negative signs of energy (C)</p> Signup and view all the answers

<p>Only changes in energy have significance, not absolute values (A)</p> Signup and view all the answers

<p>It determines how heat and work are defined (B)</p> Signup and view all the answers

<p>Instantaneous energy change within the system (A)</p> Signup and view all the answers

<p>Work done (C)</p> Signup and view all the answers

<p>Energy is leaving the system (B)</p> Signup and view all the answers

<p>Thermal conductivity of the container (C)</p> Signup and view all the answers

<p>The relationship between the rate of heat transfer and temperature gradient. (D)</p> Signup and view all the answers

<p>It signifies the direction of energy transfer. (B)</p> Signup and view all the answers

<p>It can occur in a vacuum. (B)</p> Signup and view all the answers

<p>A constant indicating the rate of heat transfer per unit area. (B)</p> Signup and view all the answers

<p>Convection involves bulk fluid motion. (C)</p> Signup and view all the answers

<p>A series of processes that returns to the original state. (A)</p> Signup and view all the answers

<p>Newton's law of cooling. (D)</p> Signup and view all the answers

<p>It characterizes the efficiency of a surface to emit energy. (C)</p> Signup and view all the answers

<p>400 kJ (B)</p> Signup and view all the answers

<p>40% (D)</p> Signup and view all the answers

<p>Wcycle = Qout - Qin (C)</p> Signup and view all the answers

<p>Efficiency = Qin / Wcycle (D)</p> Signup and view all the answers

<p>COP = Qin / Wcycle (B)</p> Signup and view all the answers

<p>It operates on the same principle as a refrigeration cycle. (D)</p> Signup and view all the answers

<p>Energy change per cycle is zero. (C)</p> Signup and view all the answers

<p>Qin is absorbed from the cold body while Qout is released to the hot body. (B)</p> Signup and view all the answers

The sum of the kinetic energy, gravitational potential energy, and internal energy of the system.

The energy associated with the motion of the system as a whole relative to an external reference frame, like the Earth's surface.

The energy associated with the position of the system in the Earth's gravitational field.

Energy associated with the random motion of molecules within a system. It includes the energy stored in chemical bonds, intermolecular interactions, and vibrations of atoms.

The net amount of energy transferred into a closed system by heat and work.

Energy is conserved, meaning that the total energy of a closed system remains constant. It can be transferred between different forms (kinetic, potential, internal) but it cannot be created or destroyed.

A system where no mass enters or leaves the system boundary.

The energy balance for a closed system states that the change in energy within the system during a time interval is equal to the net amount of energy transferred into the system by heat and work during that time interval.

The change in potential energy of a system with mass 'm' between two states is calculated by multiplying the mass, acceleration due to gravity, and the difference in elevation between the two states.

The change in internal energy of a system relates to its chemical composition and is not easily calculated with a simple formula. It is usually found using data tables.

The total change in energy of a closed system between two states is equal to the sum of the changes in its internal energy, kinetic energy, and potential energy.

Work in thermodynamics is considered a process involving energy transfer between a system and its surroundings.

The work done on a system depends on the specific interactions that occur during the process. It is not solely determined by the initial and final states of the system.

The change in energy of a system can occur through work and heat transfer.

The value of work done depends on the force involved and how it changes with the displacement.

Work is not a property of the system or its surroundings. It is a measure of energy transfer during a process.

The net amount of energy transferred into a closed system minus the net amount of energy transferred out of the system, resulting in a change in the system's internal energy.

The rate of change of energy within a closed system, expressed as the difference between the rate of energy inflow and the rate of energy outflow.

The transfer of energy into or out of a system by means of work.

The transfer of energy into or out of a system due to a temperature difference between the system and its surroundings.

The total amount of energy contained within a system at a given time.

The change in energy content of a system between two points in time.

The energy transferred into a system by work is considered positive, while energy transferred out of the system by work is considered negative.

The energy balance equation can be applied to different systems by carefully defining the system boundary and considering the types of energy transfers that occur across that boundary.

The rate of heat transfer across a plane is proportional to the area and the temperature gradient. It's like how quickly heat flows through a wall depends on its size and how much the temperature changes.

A property of a material that describes its ability to conduct heat. Higher thermal conductivity means heat flows more easily.

Energy transferred by electromagnetic waves, like sunlight or heat radiating from a hot stove. It doesn't need a medium to travel.

The rate of thermal radiation exchange between two surfaces depends on their areas, emissivity, and temperature difference. It's like how much heat a hot object loses to the colder surrounding air.

Energy transfer between a surface and a fluid due to a combination of conduction within the fluid and bulk flow of the fluid. It's like how air warms up near a hot radiator.

An empirical parameter that describes the rate of heat transfer by convection. Higher convection coefficient means faster heat transfer.

A series of processes that starts and ends at the same state. They can be used to generate power, like how a power plant uses heat to generate electricity.

The transfer of energy by work is used to generate a useful output, like electricity from a power plant. It requires an energy input, typically from heat transfer.

The portion of heat energy added to a system that can be converted into useful work.

The portion of heat energy added to a system that is lost to the environment.

A measure of how efficiently a system converts heat energy into useful work.

The net amount of work done by a system undergoing a power cycle (like a heat engine).

A system that absorbs heat from a cold reservoir (like a freezer) and transfers it to a hot reservoir (like the room).

The net energy transfer by work to the system during a refrigeration cycle. This is usually provided by electricity.

The heat transfer of energy to the system from the cold reservoir during a refrigeration cycle.

The heat transfer of energy from the system to the hot reservoir during a refrigeration cycle.

The heat energy transferred from the system to the hot body (e.g., a dwelling) during one cycle of operation.

The heat energy transferred from the cold body (e.g., the outside air) to the system during one cycle of operation.

The net work input required to operate the heat pump during one cycle. It represents the energy needed to transfer heat from the cold body to the hot body.

The ratio of the heat energy delivered to the hot body (Qout) to the net work input required (Wcycle) during one cycle of operation. It measures how efficiently the heat pump transfers heat.

The net work input for a heat pump cycle is calculated by subtracting the heat energy taken from the cold body (Qin) from the heat energy delivered to the hot body (Qout).