perform activity 4.1 of NCERT science book of class 7th
Answers
Explanation:
HOT AND COLD
In our day-to-day life, we come across a number of objects. Some of them are hot

and some of them are cold. Tea is hot and ice is cold. List some objects you use commonly in Table 4.1. Mark these objects as hot or cold.
Do not touch objects which are too hot. Be careful while handling a candle flame or a stove.
We see that some objects are cold while some are hot. You also know that some objects are hotter than others while some are colder than others. How do we decide which object is hotter than the other? We often do it by touching the objects. But is our sense of touch
reliable? Let us find out.
Activity 4.1
Take three large mugs. Label them as A, B and C. Put cold water in mug A and hot water in mug B. Mix some cold
Make sure that water is not so hot that you burn your hand

and hot water in mug C. Now dip your left hand in mug A and the right hand in mug B. After keeping the hands in the two mugs for 2–3 minutes, put both the hands simultaneously in mug C (Fig. 4.1). Do both the hands get the same feeling?