Temperature and its Measurement | Class 6 Science Notes

7.1 Hot or Cold?

This section explores how humans perceive hotness or coldness through the sense of touch, which is subjective and can sometimes be misleading. For example, during summers, tap water feels hotter than cold water stored in an earthen pot or refrigerator. We often judge temperature by touching objects or substances. However, this sense is not always reliable. To investigate this, an activity is proposed where one dips the right hand in warm water and the left hand in ice-cold water for 1-2 minutes, then places both hands simultaneously in tap water. The right hand may feel the tap water as cool, while the left hand may feel it as warm, even though both hands are in the same water. This demonstrates that our sense of touch can give contradictory sensations depending on prior exposure, and hence cannot always be trusted to judge temperature accurately. Therefore, an objective measure of temperature is necessary.

📊 Diagram: Fig. 7.1: Feeling hotness or coldness of water by dipping hands

🧪 Activity: Activity 7.1: Let us investigate - involves dipping hands in warm, tap, and ice-cold water to observe sensations and understand the subjectivity of touch.

🔗 Connection: This section leads to the concept of temperature as an objective measure of hotness or coldness, introduced in the next section.