Question

Write a program that reads a temperature value and the letter \(C\) for Celsius or \(F\) for Fahrenheit. Print whether water is liquid, solid, or gaseous at the given temperature at sea level.

Short answer

Write a program using if-else conditions to classify water as solid, liquid, or gaseous based on input temperature and scale.

Step-by-step solution

Understanding Temperature States

At sea level, water is liquid between 0°C and 100°C, solid below 0°C, and gaseous above 100°C. In Fahrenheit, water is liquid between 32°F and 212°F, solid below 32°F, and gaseous above 212°F.

Reading Input Values

Use input functions to read two values: a numeric temperature value and a character ('C' or 'F') to indicate Celsius or Fahrenheit. Ensure correct data type conversion.

Classifying Temperature in Celsius

For Celsius input ('C'), compare the temperature value against the thresholds for liquid, solid, and gas. Print 'liquid' if 0 ≤ temperature ≤ 100, 'solid' if temperature < 0, and 'gaseous' if temperature > 100.

Classifying Temperature in Fahrenheit

For Fahrenheit input ('F'), classify the temperature using Fahrenheit thresholds: 'liquid' if 32 ≤ temperature ≤ 212, 'solid' if temperature < 32, and 'gaseous' if temperature > 212.

Implement the Program

Implement the algorithm using a branching structure (if-else conditions) to decide on the state of water. Make sure to handle both Celsius and Fahrenheit cases separately.

Test the Program

Run multiple test cases with different temperature inputs and scales to confirm correct behavior. Check the outputs for known values like 0°C/32°F, 100°C/212°F, -10°C/14°F, and 110°C/230°F.

Key concepts

conditional statements

In Python programming, conditional statements are fundamental for making decisions in a program. These statements allow a program to choose different actions based on provided conditions. The most common conditional statements are `if`, `elif`, and `else`. These are used to execute different blocks of code depending on whether a condition evaluates to `True` or `False`.

In the context of our temperature conversion problem, we use conditional statements to determine the state (liquid, solid, or gaseous) of water at a given temperature. For example:

• An `if` statement checks if the temperature is below a specific threshold (e.g., below 0°C for solid water in Celsius).
• An `elif` (else if) statement checks the next condition when the previous condition(s) are `False` (e.g., between 0°C and 100°C for liquid water).
• An `else` statement is executed if none of the previous conditions are `True` (e.g., above 100°C for gaseous water).

This structure ensures that the program properly classifies the state of water based on the input temperature and scale, whether Celsius or Fahrenheit.

temperature conversion

Temperature conversion is crucial in this exercise to understand the range of temperatures where water transitions between states. At sea level, water changes states at specific temperatures:

• For Celsius: water is solid below 0°C, liquid between 0°C and 100°C, and gaseous above 100°C.
• For Fahrenheit: these ranges correspond to below 32°F, between 32°F and 212°F, and above 212°F.

Even though temperature conversion between Celsius and Fahrenheit is not directly needed in this problem, understanding these thresholds is essential for applying the correct rules based on the input scale. The conversion formulas between these two are:

• Celsius to Fahrenheit: \[ F = \frac{9}{5}C + 32 \]
• Fahrenheit to Celsius: \[ C = \frac{5}{9}(F - 32) \]

These formulas allow conversion between the two temperature units, assisting us in cross-verifying results when dealing with different temperature scales.

input handling

Input handling in Python is vital for creating interactive programs. It involves reading and processing the user's input to use it effectively in the program. With Python, the `input()` function is commonly used to get input from the user as a string.

In our exercise, input handling includes two main parts:

• Reading the temperature value (as a number, either integer or float).
• Reading a character that represents whether the temperature is in Celsius ('C') or Fahrenheit ('F').

Proper input handling requires converting the string input from the `input()` function to an appropriate data type. Typically, the temperature value needs to be converted to `int` or `float` for numerical operations. Error handling, such as ensuring the correct data type and value range, is also an important aspect to consider in more complex programs.

By handling inputs effectively, your program can make accurate decisions based on user-provided data, allowing it to correctly determine the state of water at the given temperature.