1. Temperature
Temperature is the measure of the warmth or coldness of an object or material. It is generally measured using a device called a thermometer.
The air temperature can be measured using a thermometer. Day and night temperatures are different. Temperature can be described as being hot, mild, chilly, or freezing. Temperature is higher in the summer and lowers in the winter.
1.1 Scales of Temperature
Celsius scale:
Celsius scale is the most commonly used measurement of temperature. This scale’s units are degrees Celsius (°C). Freezing point (0°C) and the boiling point (100°C) of water.
Fahrenheit scale
It is based on 32° for the freezing point of water and 212° for the boiling point of water. The interval between the freezing point and boiling point of water has been divided into 180 equal parts.
1.2 Relationship between Celsius and Fahrenheit scale
If you are given a temperature in either the Celsius or Fahrenheit scale, you convert it in the scale by using the relation
°F = (9⁄5 × °C) + 32
Let us now use this relation and try to convert between Celsius and Fahrenheit scales using some examples.
1.3 Solved Examples
a) Convert 25°C (nice sunny day) to Fahrenheit.
Solution:
Temperature in Celsius = 25 °C
°F = (9⁄5 × °C) + 32
°F = (9⁄5 × 25) + 32
°F = 45 + 32
°F = 77
Temperature in Fahrenheit = 77°F
b) Convert 98.6 °F (normal body temperature) to Celsius.
Solution:
Temperature in Fahrenheit = 98.6 °F
°F = (9⁄5 × °C) + 32
98.6 = (9⁄5 × °C) + 32
(9⁄5 × °C) = 98.6 - 32
(9⁄5 × °C) = 66.6
°C = 66.659
°C = 37
Temperature in Celsius = 37°C
2. Reading Temperature from figures
Let us learn how to read the exact temperature with figures using the examples below.
Example: The thermometer shows the temperature inside the window on a winter morning on the Celsius scale. What is the temperature marked by this thermometer?
Solution:
The number of divisions on the Celsius scale = 5
One division = 1°C
Temperature marked on Celsius scale = 20°C+ 1 division = 20°C + (1 × 1°C )
= 20°C + 1°C = 21°C
Example: The thermometer shows the temperature of an object on a sunny day. What is the temperature reading in the Fahrenheit scale?
Solution:
The number of divisions on the Fahrenheit scale (on the left side) = 5
One division = 2°F
Temperature marked on Fahrenheit scale = 50°C + 1 division
= 50°F + (2°F ) = 52°F
