https://www.pitara.com/tags/physics-science/Recent content in Physics Science on Pitara Kids NetworkHugoen-usSat, 13 Jun 2026 21:46:31 +0530https://www.pitara.com/science-for-kids/5ws-and-h/why-does-water-stay-cool-in-matkas/Fri, 21 Feb 2003 13:54:47 +0000https://www.pitara.com/science-for-kids/5ws-and-h/why-does-water-stay-cool-in-matkas/<p>Have you ever had a drink of cool refreshing water from a &lsquo;<em>matka</em>&rsquo; or earthen clay pot placed outside? Surprisingly enough, the pots are exposed to blazing sunlight, yet the water within stays so cool. How is that possible?</p> <p>This is because of a physical process known as evaporation. When a liquid changes to a gaseous (or vapour) state without boiling, it is known as evaporation.</p> <p>A matka is made of mud and has many minute pores (extremely small holes). No matter how tightly you pack the mud, these pores remain. It is through these pores that the water, placed inside the matka, oozes out. Now, to evaporate, the water needs to absorb heat, which will change it to vapour.</p>https://www.pitara.com/science-for-kids/5ws-and-h/whys-it-hard-for-ketchup-to-flow/Mon, 21 Feb 2005 04:40:13 +0000https://www.pitara.com/science-for-kids/5ws-and-h/whys-it-hard-for-ketchup-to-flow/<p>Why is it so tough to get ketchup out of the bottle?</p> <figure class="image-portrait-right has-caption"> <a href="https://www.pitara.com/media/5wh-173_1.gif" aria-label="Link to larger image"> <img src="https://www.pitara.com/media/5wh-173_1_hu_beb5bccd032af154.gif" width="450" height="563" alt="Why&#39;s it hard for Ketchup to flow? [Illustration by Shinod AP]" loading="lazy"> </a> <figcaption>Why&rsquo;s it hard for Ketchup to flow? [Illustration by Shinod AP]</figcaption> </figure> <p>When you overturn a sauce bottle that has been left untouched for some time, chances are, either the sauce will not come out at all or a gigantic blob will plop down on your plate. Getting ketchup to ‘flow’ out of the bottle can be quite an ordeal.</p>