Feel temperature in Temperature and its Measurements – Class 7 Science Experiment
Chapter Name: Temperature and its Measurements
Activity Name: Feel temperature in Temperature and its Measurements
Activity Description:
In this experiment, we will explore the perception of hotness and coldness by immersing our fingers in three different vessels containing cold water, hot water, and lukewarm water.
We will observe how our fingers react to the varying temperatures and discuss the subjectivity of temperature perception.
Required Items:
- Three different vessels
- Cold water
- Hot water
- Lukewarm water
Step by Step Procedure:
- Take three different vessels and fill them with cold water, hot water, and lukewarm water.
- Immerse your left hand finger in the cold water vessel and your right hand finger in the hot water vessel simultaneously.
- Keep your fingers immersed for about two to three minutes, allowing them to adapt to the respective temperatures.
- After the specified time, take off both your fingers from the cold and hot water vessels.
- Dip both fingers, one from each hand, into the lukewarm water vessel at the same time.
Experiment Observations:
- When you immerse your fingers in cold water, you will feel a sensation of coldness.
- When you immerse your fingers in hot water, you will feel a sensation of heat.
- After immersing your fingers in cold and hot water, when you dip them into the lukewarm water, you will notice that the finger which was in cold water will perceive the lukewarm water as warm, while the finger which was in hot water will perceive the lukewarm water as relatively cool.
Precautions:
- Be cautious while handling hot water to avoid burns or scalds.
- Ensure the vessels used are clean and free from any contaminants.
Lesson Learnt from Experiment:
This experiment demonstrates that the perception of hotness and coldness is subjective and relative to the initial temperature experienced. When we dip our fingers in cold water and then in lukewarm water, the lukewarm water feels warm in comparison. On the other hand, if we dip our fingers in hot water first and then in lukewarm water, the lukewarm water feels cool in comparison.
It also highlights the limitation of using touch alone to determine the exact temperature of a substance. The perception of hotness or coldness can vary based on our previous exposure to different temperatures. Objective temperature measurements using appropriate instruments are essential for accurately determining the temperature of a substance.
