Physics Chapter 21: Temperature and Heat

Questions and Answers

What is temperature?

The amount of heat energy in an object

The quantity that tests how hot or cold something is compared with a standard (correct)

The measure of the density of a substance

The force of particles in an object

What is a result of kinetic energy?

Temperature

What is the formula for kinetic energy?

KE: 1/2mv²

Not all particles in an object have the same ______.

energy Signup and view all the answers

What does 0° Kelvin represent?

absolute zero Signup and view all the answers

What is heat?

The energy transferred due to a temperature difference Signup and view all the answers

Matter contains energy, not ______.

heat Signup and view all the answers

Heat always flows from where to where?

high temperatures to low temperatures Signup and view all the answers

What is thermal energy?

The energy resulting from heat flow Signup and view all the answers

What is thermal contact?

Heat flow from one substance to another when in contact Signup and view all the answers

What is thermal equilibrium?

When objects in thermal contact reach the same temperature Signup and view all the answers

What is internal energy?

The grand total of all energies inside a substance Signup and view all the answers

How is heat measured?

By measuring a temperature change of a known mass of water Signup and view all the answers

What is a calorie?

The amount of heat required to raise the temperature of 1 gram of water by 1°C Signup and view all the answers

What is a kilocalorie or Calorie?

1000 calories Signup and view all the answers

How many joules are in 1 Calorie?

4180 J Signup and view all the answers

What is specific heat?

The quantity of heat required to raise the temperature of 1 kg of the substance by 1°C Signup and view all the answers

What happens to the motion of molecules in a substance when heated?

They move faster Signup and view all the answers

What happens to the motion of molecules in a substance when cooled?

They move slower Signup and view all the answers

What is a bimetallic strip?

Two strips of different materials stuck together Signup and view all the answers

Water has a much higher [blank] for storing energy than most materials.

heat capacity Signup and view all the answers

What happens to water at 4°C?

It contracts the most and is the most dense Signup and view all the answers

Study Notes

Temperature and Heat

Temperature measures how hot or cold an object is relative to a standard.
It results from the kinetic energy of particles within an object.
Kinetic energy (KE) is calculated using the formula: KE = 1/2 mv².

Energy and Particle Motion

Not all particles in an object possess the same energy level.
At 0° Kelvin, known as absolute zero, there is no kinetic energy and all particle motion ceases.

Heat Transfer

Heat is energy transferred between objects due to a temperature difference.
Matter contains energy rather than heat itself.
Heat naturally flows from areas of high temperature to areas of low temperature.

Concepts of Thermal Energy

Thermal energy results from heat flow and is derived from the internal energy of particles.
Thermal contact refers to heat transfer when two substances are in direct contact.
Thermal equilibrium occurs when two objects in contact reach the same temperature, and heat transfer ceases.

Internal Energy

Internal energy is the total of all forms of energy (potential, kinetic, etc.) within a substance.

Measurement of Heat

Heat transfer can be measured via the temperature change of a known mass of water absorbing heat.
A calorie is defined as the heat required to raise the temperature of 1 gram of water by 1°C.
A kilocalorie (Calorie) equals 1000 calories.
1 Calorie is equivalent to 4180 joules.

Specific Heat and Molecular Motion

Specific heat is the heat needed to increase the temperature of 1 kg of a substance by 1°C.
When heated, molecules in a substance move faster, while cooling causes them to move slower.

Bimetallic Strip

A bimetallic strip consists of two strips made from different materials, which expand at different rates.

Water's Unique Properties

Water exhibits a remarkably high heat capacity, making it efficient in energy storage.
At 4°C, water experiences the greatest contraction and is at its most dense.

Studying That Suits You

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Test your understanding of temperature, heat, and expansion with this flashcard quiz. Dive into key concepts like kinetic energy and particle behavior at different temperatures. Perfect for Physics enthusiasts looking to reinforce their knowledge!