[Physics Class Notes] on Relation Between Fahrenheit and Celsius Pdf for Exam

Fahrenheit and Celsius are the two scales widely used for measuring temperature. The temperature in the Fahrenheit scale is expressed or written in degrees Fahrenheit, and the temperature in the Celsius scale is expressed or written in degree Celsius. The relationship between Fahrenheit and Celsius is directly proportional. Besides, both Fahrenheit and Celsius have a different values for the freezing point of water, and both have a different unit difference between each scale.

What are the Units of Fahrenheit and Celsius?

For differentiating the temperature of one scale from another, the units of temperature scale prove to be extremely beneficial. °C denotes the temperature in the Celsius scale, and °F denotes the temperature in the Fahrenheit scale.

 

What is the Relationship Between C and F?

The relation between C and F shows that both Celsius and Fahrenheit are directly proportional to each other. To be specific, it implies that as the temperature in the Celsius scale increases, the temperature in the Fahrenheit scale also increases. Additionally, when the temperature in the Celsius scale decreases, the temperature in the Fahrenheit scale also decreases. Both the Celsius and Fahrenheit scales have their respective thermometer for measurements.

On the Fahrenheit scale:

32°F = the freezing point of water. 

212°F = the boiling point of water. 

On the Celsius scale:

 0°C = the freezing point of water.

100°C = the boiling point of water.

 

Conversion From Celsius to Fahrenheit 

The following mathematical formula shows the conversion from Celsius to Fahrenheit:

F = ( 9/5 * C) + 32

Where F refers to the temperature in Fahrenheit, and C refers to the temperature in the Centigrade scale. 

 

Conversion From Fahrenheit to Celsius

The following mathematical formula shows the conversion from Fahrenheit to Celsius:

C = 5/9 (F – 32)

Where F refers to the temperature in Fahrenheit, and C refers to the temperature in the Centigrade scale. 

Degree Celsius To Fahrenheit 

For converting 1 degree Celsius to Fahrenheit, we will use the following formula:

F = ( 9/5 * C) + 32

Where F refers to the temperature in Fahrenheit, and C refers to the temperature in the Centigrade scale. 

In this particular case, the value of C = 1. So, we will substitute the value of C, and find the value of F.

F = ( 9/5 * 1) + 32

F = ( 9/5 ) + 32

F = (9 + 160)/5

F = (169)/5

F = 33.8

So, 1 degree Celsius = 33.8°F

Degree Fahrenheit To Celsius

For converting 1 degree Fahrenheit to Celsius, we will use the following formula:

C = 5/9 (F – 32)

Where F refers to the temperature in Fahrenheit, and C refers to the temperature in the Centigrade scale. 

In this particular case, the value of F = 1. So, we will substitute the value of F, and find the value of C.

C = 5/9 (1 – 32)

C = 5/9 (- 31)

C = – 155/9

C = – 17.2222

So, 1 degree Fahrenheit = – 17.2222°C

 

Solved Examples:

Question 1

Convert 12°F to Celsius. 

Answer:

For converting 12°F to Celsius, we will use the following formula:

C = 5/9 (F – 32)

Where F refers to the temperature in Fahrenheit, and C refers to the temperature in the Centigrade scale. 

In this particular case, the value of F = 12. So, we will substitute the value of F, and find the value of C.

C = 5/9 (12 – 32)

C = 5/9 (-20)

C = – 100/9

C = – 11.11

So, 12°F = – 11.11°C

 

Question 2

Convert 30°C to Fahrenheit. 

Answer:

For converting 30°C to Fahrenheit, we will use the following formula:

F = ( 9/5 * C) + 32

Where F refers to the temperature in Fahrenheit, and C refers to the temperature in the Centigrade scale. 

In this particular case, the value of C = 30. So, we will substitute the value of C, and find the value of F.

F = ( 9/5 * 30) + 32

F = ( 9 * 6) + 32

F = 54 + 32

F = 86

So, 30°C = 86°F

The history of the Celsius and Fahrenheit Scales of Temperature

Of the two, the Fahrenheit Scale was invented first. It was invented by the physicist Daniel Gabriel Fahrenheit I’m 1724, who based his scale on the freezing temperature of brine and his estimation of the average inner body temperature of a person. Brine, which is a solution of water, ice, and ammonium chloride (a type of salt) was estimated to freeze at 0°F according to his scale. On the hotter side of the scale, he estimated that the average human’s internal body temperature would be around 90°F, a figure that he later revised to 96°F. Daniel Gabriel Fahrenheit came quite close with that latter estimate, as we now know that the average human’s internal body temperature is around 98°F.

The Celsius Scale was developed around 20 years after the Fahrenheit Scale, in 1742. The inventor of the scale was named Anders Celsius, after whom the scale is named. However, that was not his original name for it. The name he gave, which was used for the next couple of centuries before being changed, was the Centigrade Scale. This name was given because of the base of the calculation. In his scale, Celsius estimated that the melting point of snow would be around 0°C while the boiling point of water would be 100°C. This 100 point difference led to the name Centigrade, coming from the Latin words centum meaning 100 and gradus meaning steps. 

Most places that follow the metric system use the Celsius Scale as the main measurement of temperature, while other places use the Fahrenheit Scale. However, scientific research all over the world uses the Celsius Scale.

You can click here to learn how to convert from Celsius to Fahrenheit and vice versa.