Answers TX-Physics CRFirst Law of Thermodynamics

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Which best describes a wave?

a collision of particles

a disturbance that carries energy

a movement of fluids

a group of electrically charged molecules

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Five hundred joules of heat are added to a closed system. The initial internal energy of the system is 87 J, and the final internal energy is 134 J.

221 J

279 J

366 J

453 J

Rosa pours a cup of boiling water into a pot of room-temperature water. According to the second law of thermodynamics, what will occur?

Thermal energy from the room-temperature water will continuously flow to the boiling water.

Thermal energy from the room-temperature water will flow to the boiling water until all of the water in the pot is at a single temperature.

Thermal energy from the boiling water will continuously flow to the room-temperature water.

Thermal energy from the boiling water will flow to the room-temperature water until all of the water in the pot is at a single temperature.

A steam turbine is a device in which high-pressure steam enters the turbine and causes blades to spin. The spinning blades have mechanical energy.

The turbine absorbs heat, which creates kinetic energy in the system and produces work to turn the blades.

The turbine destroys some of the thermal energy in the steam, which generates work and turns the blades.

The turbine generates heat from the steam, and some of the heat creates work and turns the blades.

Some of the heat used to make the steam is transformed into work as the steam pushes against the blades to make them turn.

Which two conditions must exist in order for radiation to occur?

the presence of a solid, liquid, or gas and a temperature difference

direct contact of molecules and the presence of a solid, liquid, or gas

the presence of electromagnetic waves and direct contact of molecules

a temperature difference and the presence of electromagnetic waves

Water has a specific heat of 4.186 J/g°C. How much heat is required to increase 10.0 g of water from 25.0°C to 30.0°C?

5.0 J

21 J

42 J

209 J

Three hundred joules of heat are added to a system. The system uses 140 joules to do work.

140 J

160 J

240 J

440 J

Which best compares kinetic energy and temperature?

Kinetic energy is energy of motion, while temperature is a measure of that energy in substances.

Temperature is energy of motion, while kinetic energy is a measure of that energy in substances.

Kinetic energy is internal transferable energy, while temperature is a measure of that energy in substances.

Temperature is internal transferable energy, while kinetic energy is a measure of that energy in substances.

Which is an example of convection?

In a mountain forest, the sun heats up the ground.

On a hot day, Amaya pours water on her face to cool off.

At the beach, Stephan’s feet get hot walking across the sand.

Above the sea, warm air rises, cools, and sinks.

The diagram shows the movement of air as a result of convection currents.

Nya has a cup of hot tea that she lets cool down for several minutes. What effect does cooling have on the tea?

Its particles have less kinetic energy.

Its particles have more kinetic energy.

Its specific heat increases.

Its specific heat decreases.

Sienna made a chart listing the steps that describe how a four-stroke heat engine operates.Which best describes Sienna’s error?

The descriptions for intake and ignition should be switched with one another.

During compression, temperature does not increase, it decreases.

Compression happens before ignition, so it should be step 2.

The piston moves down, not up, during the exhaust step.

Suppose the spark plug on a heat engine is not functioning properly. Which statement best explains how this will affect the engine?

The temperature of the gas will not increase during the compression stage.

Burned gases will not be released into the surrounding air.

The fuel-air mixture will not be able to enter the cylinder.

Combustion and subsequent gas expansion will not occur.

Dierdra began writing a summary of the relationship between the first and second laws of thermodynamics.Thermal energy in a system is conserved and can increase the system’s internal energy and/or be used to do work.

Thermal energy moves from cooler objects to warmer objects

Thermal energy moves from warmer objects to cooler objects.

Thermal energy is destroyed when it leaves the system.

Thermal energy is created when it enters the system.

[BLANK]

transferred

changed

created

measured

The diagram shows a heat engine.

A system uses 49 J of energy to do work, and the change in internal energy is 58 J. How much heat was added to the system?

9 J

97 J

107 J

117 J

Which best describes the first law of thermodynamics as compared to the second law of thermodynamics?

The first law describes how thermal energy is conserved but not the direction it moves.

The first law describes the direction thermal energy moves but not how it is conserved.

The first law describes how thermal energy can be created but not how it can be destroyed.

The first law describes how thermal energy can be destroyed but not how it can be created.

It requires 2,500 joules to raise a certain amount of water (c = 4.186 J/g°C) from 20.0°C to 60.0°C.

15 g

40 g

63 g

80 g

When the kinetic energy of particles in a substance decreases, what also decreases?

The size of the particles in the substance.

The number of particles in the substance.

The substance’s specific heat.

The substance’s temperature.

Elements with low specific heat values have which characteristic?

low atomic mass

high thermal energy

low kinetic energy

low number of atoms per gram

Dante pours hot tea into a mug that is cool to the touch. Which best explains what will happen now?

The tea will get warmer because the mug acts as a thermal insulator.

The tea will get cooler because it gains energy from the mug.

The mug will get warmer because thermal energy transfers from the tea to the mug.

The mug will get warmer because the tea creates more thermal energy inside the mug.

Which best describes the relationship between heat, internal energy, and thermal energy?

Internal energy is heat that flows, and heat is the part of thermal energy that can be transferred.

Internal energy is thermal energy that flows, and thermal energy is the part of heat that can be transferred.

Thermal energy is heat that flows, and heat is the part of internal energy that can be transferred.

Heat is thermal energy that flows, and thermal energy is the part of internal energy that can be transferred.

Thermal energy from the Sun travels to Earth by

conduction.

charged molecules.

electromagnetic waves.

convection currents.

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