EXPERIMENTS WITH WATER-TEXT

EXPERIMENTS WITH WATER

ENVIRONMENTAL STUDIES

CBSE-V

What floats – what sinks?

Ayesha was waiting for dinner. Today Ammi was making her favourite food – puri and spicy potatoes. Ayesha watched as her mother rolled out the puri and put it in the hot oil. She saw that at first the puri sank to the

bottom of the pan.

As it puffed up, the puri came up and started floating on the oil. One puri did not puff up and did not float like the others. On seeing this, Ayesha took some dough and rolled it into a ball. She flattened it and put it in

a bowl of water.  Alas! it sank to the bottom and stayed there.

In the evening Ayesha went for a bath. She had just come out when her mother called, “Ayesha, you have dropped the soap in the water again.

Take it out and put it in the soap case.” Ayesha was in a hurry and the soap case fell out of her hands. It started floating on water. Ayesha

gently put the soap in the soap case. She saw that the case continued to float, even with the soap in it.

A wooden boat in water will float. But a needle will sink! Why does this happen?

Let me think... An iron ship will also float, though its’ much heavier

than my boat!

Archimedes' Principle of Buoyancy:

Archimedes' principle indicates that the upward  buoyant force that is exerted on a body immersed in a  fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces.

Because The reason that a ship floats is that it displaces a lot of water. The displaced water wants to return to it's original location, where the ship is now, and this pushes the ship upwards. The force which pushes the ship up is called the buoyancy force.

Archimedes continued to do more experiments and came up with a buoyancy principle, that a ship will float when the weight of the water it displaces equals the weight of the ship and anything will float if it is shaped to displace its own weight of water before it reaches the point where it will submerge.

This is kind of a technical way of looking at it. A ship that is launched sinks into the sea until the weight of the water it displaces is equal to its own weight. As the ship is loaded, it sinks deeper, displacing more water, and so the magnitude of the buoyant force continuously matches the weight of the ship and its cargo.

But a needle, light as a leaf, thin as a pin, will sink right in! Why does this happen?

The density of nail (as of iron) is much larger than the water. So it sinks easily. The weight of the water displaced by the ship is equal to its weight, so it floats. Whereas the weight of the water displaced by the iron nail is less than its weight so the iron nail sinks.

Have you seen that some thing float on water while others sink? Think how this happens! The poem here raises such questions.

Dead Sea:

All oceans and seas have salty water. The saltiest of all is the Dead Sea. How salty? Imagine 300 grams of salt in one litre of water! Would you be able to even taste such salty water? It would be very bitter.

Interestingly, even if a person does not know how to swim, she would not drown in this sea. She will float in water, as if lying down on it!

Remember the lemon you floated in salty water?

What dissolved, what did not?

On Sunday Ayesha’s cousin brother Hamid came to her house

to play. As soon as he came he asked his aunt to make his favourite shakkarpara (a sweet dish).

Ammi said, “Let me come back from the market, then I will make some for you. Why don’t you help me? Take two glasses of water and put a bowl of sugar in it. Mix it till it dissolves.” Hamid thought, “Let me

finish this work fast. Then I will watch TV”.

Dandi March:

This incident took place in 1930, before India became independent. For many years the British had made a law that did not allow people to make salt themselves.

They had also put a heavy tax on salt. By this law people could not

make salt even for use at home. “How can anybody live without salt?” Gandhiji said, “How can a law not allow us to use freely what nature has given!” Gandhiji, with several other people, went on a yatra (long walk) from Ahmedabad to the Dandi seashore in Gujarat, to protest against

this law.

Do you know how salt is made? The sea water is collected in shallow beds dug in the sand. Water is allowed to dry in the sun. After

the water dries the salt remains on the ground.

THANKYOU,

NANDITHA AKUNURI

EVER DROP COUNT-TEXT

EVER DROP COUNT

ENVIRONMENTAL STUDIES

CBSE-V

Long Long Ago:

This is a picture of Ghadsisar. Sar means a lake. King Ghadsi of Jaisalmer got it made 650 years ago with the help of the people.

All around the lake there are ghats with steps leading to the water, decorated verandahs, large halls, rooms and much more. People came here to celebrate festivals and for programmes of music and dance.

Children came to study in the school on the ghat. The talab belonged to everyone and everyone took care to keep it clean.

Rainwater collected in this lake spread over many miles. It was made in such a way that when the lake was full, the extra water flowed into another lake at a lower level.

When that too filled up, the extra water flowed into the third lake and so on  filling nine such interconnected lakes. The collected rain water could be used throughout the year and there was no shortage of water.

Today, Ghadsisar is no more in use. Many new buildings and colonies have come up in between those nine lakes. Now the water does not get collected in these lakes but just flows away and is wasted.

Through the eyes of Al-Biruni :

One of the most famous of the historic accounts of India is that written in Arabic by al-Biruni nearly a thousand years ago. 

Al-Biruni is regarded as one of the greatest scholars of the medieval Islamic era and was well versed  in   physics, mathematics, astronomy, and natural science, and also distinguished himself as a chronologist, historian, and linguistic.

He spent a large part of his life time in  ghazni in modern-day Afghanistan and the capital city of the   ghaznavid dynasty.which was based in what is now central-eastern Afghanistan.

In 1017 he traveled to the Indian subcontinent and authored “Tarikh Al-Hind” -History of India,  after exploring the Hindu faith practised in India. He is given the titles the "founder of indology ".

More than a thousand years ago, a traveller came to India.The place that he came from is now called Uzbekistan.

Al-Biruni carefully observed and noted down the details of all that he saw. He wrote especially about those things that he found very different from his own country. Here is a part of what he wrote about the ponds of that time. The people here are very skilled at making ponds. My countrymen would be surprised to see them. They pile up huge

rocks and join them with iron rods to build chabutaras (raised platforms) all around the lake. Between these, there are rows of long staircases, going up and down.

The steps for going up and coming down are separate. So there is less crowding. Today when we study history, we can learn a lot about those days from the writings of Al-Biruni. (This stamp came out in 1973, one

thousand years after his birth.)

Drop-by-drop:

Jaipur is the capital and largest city of the state of Rajasthan, India. Jaipur became the capital of Rajasthan after Independence in 1956.

Jaipur is currently experiencing growing water scarcity and diminishing drinking water sources, relying extensively on groundwater and a single surface water source, the Bisalpur Dam, which is shared with Ajmer and villages in the Tonk District and located 120 kilometers southwest of Jaipur.

Scorching heat coupled with water crisis has made life very difficult for people in Rajasthan. In at least 24 many cities and towns of the state including Barmer, Jalore, Makrana, Rajgarh, Balotra water is being supplied only once in four days.

Camels are being used to pull water tankers instead of ferrying people. At every boring well in the state rows of camels with water tanks are seen.

Besides Jaisalmer, many places in Rajasthan, get very little rainfall. Here it rains for only ten to twelve days in the entire year, sometimes not even that much. The rivers here do not have water in them all round the year.

And yet, most of the villages in these areas did not have a shortage of water. People knew that every drop of water was precious. Lakes and johads were made to collect these precious drops of water.

Water was everyone’s need. One and all came together in this work – be it a businessman or a labourer. Some water from the lakes soaked into the ground and reached the wells and bavdis

(stepwell) in that area.

The soil of the area also became wet and fertile. Every house had a system to collect the rain water. Look at this picture.

How do you think the rainwater that falls on the roof will reach the

underground tank?

Draw the path:

Have you ever seen a stepwell? Look at the picture. Can you imagine by looking at the picture that the steps go down several storeys deep?

Instead of drawing the water up from the well, the people could go down the steps and reach the water. That is why they are called stepwells.

Long ago, people used to make long journeys with their caravans of animals and goods. People felt it was a good thing to give water to thirsty travellers. Thus, they built many beautiful stepwells.

Customs related to water:

Even today people get water from very old lakes, dharas, stepwells and naulas. Many customs and festivals are related to water.

At some places, whenever lakes get filled up with rainwater, the people

gather around the lake to celebrate.

See the bride of Uttarakhand in this picture. After getting married she has come to the new village. She bows to the spring or the pond. In cities

one can see an interesting form of this custom.

The new bride worships the tap in her home. Can we even imagine life

without water? Devraj

Think over it:

In 1986, there was no rain in Jodhpur and the surrounding areas. People remembered the old and forgotten stepwell (baoli). They cleaned the stepwell and more than two hundred trucks of garbage was taken out of it. People of the area collected money.

The thirsty town got water from the stepwell. After a few years it rained well and again the stepwell was forgotten.

There are two old wells in the area where Punita lives. Her grandmother says that about fifteen - twenty years ago there was water in these wells. The wells could have dried up because:

Water is being pumped up from under the ground, with the help of electric motors.

The lakes in which rain water used to collect are no longer there. The soil around trees and parks is now covered with cement.

This is how we get water:

A Jal Board water tanker comes to our colony twice a day. We have to stand in a long queue to get water from the tanker. People at times We fill water from the well.

The nearby well dried up a year ago. Now we have to walk far to reach the other well.

We are not allowed to take water from some of the wells because of our caste. have fights over water. We get water at home for half an hour. We fill this in the tank to use all day. Sometime it is dirty.

We get water from our taps, all day long.

We have put a pump directly in the Jal Board pipeline. Now we don't have any problem! We have put a motor to pump up the water from the borewell. But there is no electricity, so what do we do!

There is a handpump nearby, but the water that we get from it is salty. We have to buy water for drinking.

We get water from the canal itself.

It can be done:

There are some groups that work hard to bring water to the people of different areas. They ask the elders about the water arrangement in their times.

They rebuild the old lakes and johads, and also build new ones. Let us see how the group called Tarun Bharat Sangh helped Darki Mai. This is Darki Mai. She lives in a village in the Alwar district of

Rajasthan.

The women of the village used to spend the entire day looking after their home and animals. Sometimes, it took them all night to pull water from the well for the animals. In the summer, when the wells dried up, they had to leave the village.

Darki Mai heard about this group and asked for help. Together, the people from the group and the village decided to make a lake. The problem of food and water for animals is now less. People get more milk. They have started earning more.

THANKYOU,

NANDITHA AKUNURI

SEEDS AND SEEDS-TEXT

SEEDS AND SEEDS

ENVIRONMENTAL STUDIES

CBSE-V

Children in these lesson we are going to learn about seed germination and dispersal of seeds.

Gopal was waiting for his mausi’s family to visit them. They will be coming the next day for their holidays. He was thinking about all the fun and nice food that he would have with his cousins.

Just then his mother called out, “Gopal, before you sleep, remember to soak two small bowls (katoris) of chana (gram).” She was going to his Bua’s house and would return only in the morning.

As he was soaking the chana, Gopal thought, “How will two small bowls of this be enough for eight persons?” So he soaked another two bowls of chana.

When his mother returned the next morning, she saw that the chana were overflowing from the vessel. “How much did you soak?” asked his mother. “How did that happen!” wondered Gopal.

“You soaked too much! Anyway it is good, now I will cook half of them, and leave the other half to sprout. I can send these to your aunt. The doctor has told her to eat sprouts”, mother said. She tied half of the soaked chana in a wet cloth, and hung them up to sprout.

Let us see about seed germination:

Growing plants from seeds:

Children if u eat an apple or an orange you will fine deeds inside. New plants can grow from these seeds.

Not all seeds grow into new plants . some seeds are eaten up by birds and insects. Some seeds get destroyed by the rain or wind. If seeds get sufficient amount of air, water, warmth it grows in to new plant .

 A seed producing a new bady plant  or seedling . this process we called as seed germination.

During the early stages of germination , the sedling gets the foods which ift requires for its growth from the cotyledous. The food which stored in cotyledous has been used up the seedling gets its food from the soil.

The seddlings absorbs water and nutrients from the soil with the help of its roots. The it develops new leaves and grows in to a new abay plant.

Now it requires air for seed germination. The air reaches the seed through pores in the soil. That is why soil is so important for plants growth.

Afte they germinate, they will struggle for air, water, light, nutrients and the space to grow. As a result, many of them would die.

Structure of seed:

Children have you seen a bean or a gram seed. It is hard and cannot be broken easily. The hard outer covering layer is alled the seed coat. The seed coat protects the sed.

 The seed has two cotyledons. These are special seed leaves which protect baby plant or embryo. They also store food for the embryo.

Seeds like grmas, beans and peas have two cotyledons while seeds like wheat and corn have only one cotyledon.

Let us see about seed dispersal:

Seed Dispersal: The process by which seeds are scattered away from the mother  plant is called dispersal.

Seed Dispersal By Water: some plants of seeds like lotus and coconut are spongy in nature or they have a fibrous covering, on they outer surface. This help them to float on water easily. Water carries these seeds easily from one place to another. this type if dispersal is called as Seed Dispersal by water.

Example: lotus, coconut and water lilly.

Seed Dispersal By Wind: some seeds of certain plants are very light in weight and have wing-like structures or hair on them. These type of seeds can easily carried away by the wind from one place to another place. This type if dispersal is called as Seed Dispersal by wind.

Examples: Plants like cotton, dandelion and madar.

Seed Dispersal By Explosion: the fruits of some plants just like poppy, pea and bean. These fruits can burst and open when they ripe, scattering the seeds in all directions . this type if dispersal is called as Seed Dispersal by explosion.

Examples: fruits like pea and balsam.

Seed Dispersal By Animals: some plants cocklebur seeds have spine or hooks on their body. These seeds stick to the bodies of animals and birds. So they carried away from the mother plant. this type if dispersal is called as Seed Dispersal by animals.

Examples: plants like xanthium,tigernailsma and spear grass.

These are the various types of dispersal of seeds which grows in to a new baby plant.

A SMALL STORY:

This happened in 1948. One day George Mestral came back from a walk with his dog. He was amazed to find seeds sticking all over his clothes and on his dog’s fur. He wondered what made them stick. So he observed these seeds under a microscope. He saw that the seeds had many tiny hooks which got stuck to clothes or fur. This gave Mestral the idea of making Velcro. He made a material with similar tiny hooks that

would stick. Velcro is used to stick together many things – clothes, shoes, bags, belts and many more. What a way to take inspiration from nature!

Who came from where:

Have you included human beings also in your list? Yes, we also carry seeds from one place to another, knowingly or unknowingly. We bring the seeds of plants that we find beautiful or useful, to grow them in our garden.

Later the seeds of these plants spread to other places. Many years later people may not even remember that these plants did not grow here earlier. They were brought from somewhere else. Here some of the seeds they dispersal from one place to another

Do you know from where chillies came to our country? These were brought to India by traders coming from South America. Today we cannot think of food without chillies!

From South America long ago, came a tomato, a potato, and a green chilli. Do you know this?

A cabbage came from Europe, and also a pea. From Africa came a coffee bean, and a green bhindi.

A mango sang, ‘Come in! Come in!’ An orange smiled inside its skin. ‘Welcome to India,’ a banana said. the methi and spinach, brinjal and radish, nodded its head.

Pants from sopres:

Some plants like fren, fungi and moss do not have flowers. So, they do not not produce seeds. They produce tiny spores. This spores develops into new baby plant.

Plants grow different body parts;

Some plants grow from the body parts of the parent plant. The method of obtaining new plants from the leaves, stem and roots of the parent plant is called vegetative propagation.

Plants like potato and ginger have eyes on them. Under suitable conditions they grow in to a bud from new baby plant growa.

Onion and ginge plants also grow from their underground bulb –shaped stems.

Plants like bryophyllum, gorws from the edges of leaves buds.

Some plants grows from buds on the stem examples rose hibiscus, sugarcane etc.

THANKYOU,

NANDITHA AKUNURI 

FROM TASTING TO DIGESTING-TEXT

FROM TASTING TO DIGESTING

ENVIRONMENTAL STUDIES

CBSE-V

Different tastes:

Taste buds are sensory organs that are found on yourTONGUE and allow you to experience tastes that are sweet, salty, sour, and bitter. How exactly do your taste buds work? Well, stick out your tongue and look in the mirror.

Taste buds contain the receptors for taste. They are located around the small structures on the upper surface of the tongue, soft palate, upper esophagus, the cheek, epiglottis, which are called papillae. The myth of the tongue map; that 1 tastes bitter, 2 tastes sour, 3 tastes salt, and 4 tastes sweet.

Jhumpa ran into the kitchen and caught hold of her mother saying, “Ma, I am not going to eat this bitter karela (bittergourd). Give me gur (jaggery) and roti.”

 Ma smiled and said, “You ate roti and sugar in the morning.” Jhoolan teased Jhumpa, “Don’t you get bored of only one kind of taste?” Jhumpa replied quickly, “Do you get bored with licking imli (tarmarind)? I bet your mouth is watering just by hearing the word imli.”

 “Sure I love the sour imli. But I eat sweet and salty things too. I even eat karela,” said Jhoolan and looked at her mother.

They both laughed heartily. Jhoolan said to Jhumpa, “Let’s play a game. You close your eyes and open your mouth. I will put something to eat in your mouth. You have to tell what it is.”

Jhoolan took a few drops of lemon juice in a spoon and put them in Jhumpa’s mouth. “Sour lemon,” Jhumpa replied quickly.

Jhoolan then picked up a small piece of jaggery. Her mother suggested, “Crush it, otherwise she will know what it is?” Jhoolan crushed the jaggery but Jhumpa easily guessed it.

They played the game with different food items. Jhumpa could tell the fried fish even before tasting it. Jhoolan said, “Now close your nose, and tell me what this is?” Jhumpa was confused, “It is a bit bitter, a little salty and somewhat sour.

Give me one more spoonful.” Jhoolan took another spoonful of the cooked karela, uncovered Jhumpa’s eyes, and said, “Here it is, eat!” Jhumpa laughed, “Yes, give me more.”

Nitu was given a glucose drip:

Nitu was very sick. All day she was vomiting and she also had loose motions. Whatever she ate, she vomited. Her father gave her sugar and salt solution. By evening Nitu was feeling weak and dizzy. When she got up to go to the doctor she fainted.

Her father had to carry her to the doctor. The doctor said that Nitu should get admitted in the hospital. She needs to be given a glucose drip. Hearing this, Nitu got confused. She knew that during the games period in school, the teacher sometimes gave them glucose to drink.

But what was a glucose drip? Doctor aunty explained, “Your stomach is

upset. Your body is not keeping any food and water and it has become very weak. The glucose drip will give you some strength quickly, even without eating.”

Story – A Stomach with a Window:

In the poem, you read about a soldier called Martin. In 1822, he was eighteen years old and was very healthy. When he was shot, he got seriously hurt. At that time Dr. Beaumont was called to treat him.

Dr. Beaumont cleaned the wound and put the dressing. After one and a half years, the doctor found that Martin’s wound had healed except for one thing.

He had a big hole in his stomach. The hole was covered with a loose flap of skin, like the washer in a football. Press the skin and you could peep into Martin’s stomach! Not only that, the doctor could also take out food from the stomach by putting a tube in the hole.

Dr. Beaumont felt he had found a treasure. Can you guess how much time he spent on doing different experiments on this stomach?

Nine years! During this time Martin grew up and got married. At that time scientists did not know how food was digested? How does the liquid (digestive juices) in the stomach help? Does it only help in making the food wet and soft? Or does it also help in digestion?

Dr. Beaumont took some liquid (juices) out of the stomach. He wanted to see what would happen to a food item kept in a glass filled with it. Would it get digested on its own? For this he did an experiment. With the help of a tube, he took out some digestive juice from the stomach.

At 8.30am he put twenty tiny pieces of boiled fish in 10 millilitres of the juice. He kept the glass at the same temperature as that of our stomach – about 30°C. When he checked at 2 pm he found that the pieces of fish had dissolved.

Dr. Beaumont tried this experiment with different food items. He gave Martin the same food at the same time and then compared how long it took for food to be digested in the glass and in Martin’s stomach. He recorded his observations in a table.

TABLE:

So, what does our stomach do? Dr. Beaumont did many experiments and found out many secrets about digestion. He found that food digests faster in the stomach than outside. Did you notice this in the table?

Our stomach churns the food to digest it. The doctor also saw that the food did not digest properly when Martin was sad. He also found that the juice in our stomach is acidic. Have you heard of anyone talking about acidity -especially when that person has not eaten well or the food is not digested properly.

Dr. Beaumont’s experiments became famous across the world. After this many scientists did many such experiments. What did you say? No, they did not shoot people in the stomach. Nor did they wait for a patient with a hole in the stomach. They used other scientific ways to look inside our bodies.

 Children Did you like the story of Martin or, should we say, the story of our own stomach?

THANK YOU,

NANDITHA AKUNURI