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NCERT Solutions For Class 8 Science Chapter 3 Coal And Petroleum Long Answer Questions

Question 1. Why is petrol an exhaustible natural resource, whereas sunlight is not? Explain
Answer:

The natural resources, which are present in a limited quantity in nature and can be exhausted (used up) by human activities, are called exhaustible natural resources, Examples include coal, petroleum, natural gas, minerals, forests, wildlife, etc.

It requires millions of years for the conversion of dead organisms into petroleum, from which petrol is separated.

NCERT Solutions for Coal and Petroleum Long Answer Questions

So, once the present stock of it gets exhausted, no new supplies of it will be available to us in the near future, whereas sunlight is present in an unlimited quantity in nature, so it isan  inexhaustible natural resource. It is not likely to be exhausted by human activities.

Now answer the following questions.

1. What is the material X?
Answer: Coal

Class 8 Science Chapter 3 Coal and Petroleum Long Answer Questions

2. What is the physical state and colour of X?
Answer: It is solid and black.

3. Name the processes Y.
Answer: Y is carbonisation.

NCERT Solutions for Class 8 Science Coal and Petroleum LAQs

4. What are the products A, B, and C?
Answer: A is coke, B is coal gas, while C is coal tar.

Question 2. The following table shows the total power shortage in India from 1991-1997. Show the data in the form of a graph. Plot the shortage percentage for the years on the Y-axis and the years on the X-axis.

Answer: Scale along X-axis, 1 unit =1 year and along Y-axis, 1 unit = 1%

Question 3. The table shows two groups of natural resources.

NCERT Solutions for Coal and Petroleum Chapter 3 LAQs

1. How is group 1 different from group 2?
Answer: 

Coal and Petroleum Class 8 NCERT LAQs

2. Which resource in group 2 will cause the least amount of air pollution on burning?
Answer: Natural gas will contribute the least amount of air pollution on burning among the resources in group 2.

NCERT Solutions For Class 8 Science Chapter 2: Very Short Answer Questions

Question 1. An ingredient is added to idlis and bhatura to make them soft. What is it?
Answer: Curd is added to idlis and bhatura to make them soft.

Question 2. A gas is responsible for the increase in the volume of dough. Name it.
Answer: Carbon dioxide given out by yeast is responsible for the increase in volume of dough.

NCERT Solutions for Microorganisms Friend and Foe VSAQs

NCERT Solutions for Class 8 Science Microorganisms VSAQs

Question 3. Yeast is used for commercial purposes. Write one commercial use of yeast.
Answer: Baking bread is one of the commercial uses of yeast. It is also used in alcohol manufacturing.

Question 4. Name the process in yeast that converts sugar into alcohol.
Answer: Fermentation is the process by which yeast converts sugars into alcohol.

Question 5. Should antibiotics be used for cold and flu? Give a reason for your answer.
Answer: No, antibiotics should not be used in cold and flu because these diseases are caused by viruses and antibiotics are not effective against viruses.

NCERT Class 8 Science Chapter 2 Microorganisms VSAQs

Question 6. Vaccines are essential for what purpose? Mention two diseases for which vaccines are available.
Answer: A Vaccine is essential to protect all children against several diseases. Polio and hepatitis are two diseases for which vaccines are available.

Question 7. Where is the mode of transmission in the yellow vein mosaic of okra?
Answer: Yellow vein mosaic of okra is a viral disease transmitted by an insect.

Microorganisms Friend and Foe NCERT Solutions for VSAQs

Question 8. We add a little curd to warm milk to set the curd for the next day. Why?
Answer: Curd contains several microorganisms. Of these, the bacterium Lactobacillus promotes the formation of curd. It multiplies in milk and converts it into curd.

VSAQs of Chapter 2 Class 8 Science Microorganisms

NCERT Solutions For Class 8 Science Chapter 2 Long Answer Questions

Question 1. Manoj adds some yeast to two test tubes containing sugar solution. He ties balloons on the mouth of each of the test tubes. One test tube is kept in ice and the other at room temperature. The picture shows what happens after three hours.

1. What In Manoj Invontignting?

1. Does yeast grow in sugar solution only?
2. Does yeast convert sugar into alcohol?
3. Does temperature affect the growth of yeast?
4. Which gas is produced as yeast grows in a sugar solution?

Answer: 3. Does temperature affect the growth of yeast?

NCERT Class 8 Science Chapter 2 Microorganisms LAQs

2. How can Manoj confirm, If the gas produced In the tost tube at room temporaturo was due to tho yeast growing In It?

1. He should repeat the same experiment
2. He should leave the test tube undisturbed for six hours
3. He should repeat the experiment with test tubes containing more sugar solution
4. He should keep an extra set of test tubes with sugar solution, but without the yeast

Answer: 4. He should keep an extra set of test tubes with sugar solution without the yeast

3. What should Manoj keep the same in both the test tubes for a fair experiment? Circle ‘Yes’ or ‘No’ for each row.

Answer:

1. Yes
2. No
3. Yes

4. What type of organism is yeast?

1. Fungi
2. Algae
3. Bacteria
4. Protozoa

Answer: 1 Fungi

NCERT Solutions for Microorganisms Friend and Foe LAQs

Question 2. How can we prevent the following diseases?

1. Cholera
Answer: Cholera. By maintaining personal hygiene and good sanitation practices.

2. Typhoid
Answer: Typhoid. By eating properly cooked food, drinking boiled water, and getting vaccinated against the disease.

3. Hepatitis-A
Answer: Hepatitis. By drinking boiled water and getting vaccinated against the disease.

NCERT Solutions for Class 8 Science Microorganisms LAQs

Question 3. Give reasons for the following.

1. Fresh milk is boiled before consumption, while processed milk is stored in packets and can be consumed without boiling.
Answer: Fresh milk is boiled before consumption to kill the microorganisms in it. But packed milk is pasteurised and does not contain any microorganisms. Thus, it can be consumed without boiling.

2. Raw vegetables and fruits are kept in refrigerators, whereas jams and pickles can be kept outside.
Answer: Raw vegetables and fruits get easily infected by microorganisms and get spoiled. They are kept in the refrigerator at a low temperature inhibits the growth of microbes. Jams and pickles contain sugar and salt as preservatives. They do not get infected by microbes, as these preservatives do not allow the growth of microbes.

NCERT Class 8 Microorganisms Friend and Foe LAQs

3. Farmers prefer to grow beans and peas in nitrogen-deficient soils.
Answer: Beans and peas are leguminous plants and have Rhizobium in their root nodules. These bacteria can fix atmospheric nitrogen to enrich the soil with nitrogen and increase its fertility.

4. Mosquitoes can be controlled by preventing stagnation of water, though they do not live in water. Why?
Answer: Though mosquitoes live on land, their larvae grow in water. If water stagnation is prevented, their larvae cannot survive, thus reducing the mosquito population

NCERT Solutions For Class 8 Science Chapter 2 Microorganisms: Friend And Foe SAQs

Question 1. Ankur’s mother told him to wash his hands with soap before eating because his hands might have bacteria. Ankur did not believe her because he could not see anything on his hands. Why couldn’t Ankur see the bacteria on his hands? Why is washing hands with soap and water before eating generally recommended? State how bacteria can be harmful to humans.
Answer: Bacteria are too small and cannot be seen with the naked eye. They can be seen only with the help of a microscope.That’s why Ankur could not see the bacteria on his hands. Washing hands with soap and water can help to remove various bacteria and reduce the risk of infection. Bacteria can cause various diseases like dysentery, typhoid, cholera, etc.

NCERT Solutions for Class 8 Science Microorganisms SAQs

Question 2. Name two diseases that are caused by viruses.
Write one important characteristic of a virus.
Answer:

Influenza and chickenpox are two diseases caused by viruses in humans. Viruses can reproduce only inside the cells of a host, of an infected person.

Question 3. Yeast is very useful for the baking industry. Elucidate the role of yeast.
Answer: Yeast plays an important role in the baking industry. It reproduces rapidly and produces CO2 during respiration. Bubbles fill the dough and increase its volume, making the products such as bread, cake, and fluffy.

NCERT Solutions for Microorganisms Friend and Foe SAQs

Question 4. Justify with the help of two examples that microorganisms can be beneficial for humans.
Answer: Two examples that justify that microorganisms can be beneficial for humans are as follows

Baking industry. The dough for making bread, cakes and pastries is prepared by adding yeast to flour. Yeast reproduces rapidly and produces carbon dioxide during respiration. These gases fill the dough and increase its volume. It adds sponginess to cake and bread.

NCERT Class 8 Science Chapter 2 Microorganisms SAQs

Production of Antibiotics Antibiotics are produced by several groups of microbes, such as bacteria and fungi. These microbes produce antibiotics as their natural defense system against other microbes.

Question 5. Polio drops are not given to children suffering from diarrhoea. Why?
Answer: If the child is suffering from diarrhoea, the polio drops that are orally given vaccine may be excreted because of frequent motions and thus become ineffective.

NCERT Solutions For Chapter 1 Crop Management Long Answer Questions

Question 1. Given below is a conversation between two farmers, Heera and Beera.

1. Heera: Brother Beera, your maize crops look Beautiful. They have grown pretty fast.
2. Beera: Yes, I have sprayed urea this time. What about you?
3. Heera: Well, I am still relying on good old cow dung. I am saving money to buy a tractor.
4. Beera: That’s good. A tractor saves a lot of time and labour.
5. Heera: Yes, it’s been very labour-intensive for me, and now these weeds have come up.
6. Beera: Try weedicides, they are very effective. Now, answer the following questions.
7. List the practices that are not environmentally friendly and why.
8. What is the advantage of modern agricultural implements over traditional ones?
9. Name one weedicide, and the precaution farmers must take during its application?

Answer: 

1. The practices used in the field that are not environmentally friendly are the use of fertilizers, pesticides, herbicides, and other chemical substances that pose health hazards. Tractor, though it saves labour and time, contributes to air pollution
2. Modern agricultural implements save both time and labour as compared to traditional types of equipment.
3. To crops is that they should properly cover their nose and mouth, to avoid inhaling these chemicals.

NCERT Solutions for Crop Management Chapter 1 LAQs

NCERT Class 8 Science Chapter 1 Crop Production LAQs with Answers

Question 2. A farmer wants to grow crops in his field between June and July. The chart below shows a list of crops and different agricultural practices.

Select two crops from the list that grow best during June and July.

Crop 1………Crop 2

The farmer prepared the soil in his field by turning and loosening the soil. How does turning and loosening the soil help in growing plants?

Answer: Crop 1→Paddy Crop 2 → Cotton

1. The turning and loosening of the soil helps the plants in the following ways
2. Farmers follow a sequence of agricultural practices to grow crops. A part of the sequence is shown below.
3. It brings the nutrient-rich soil to the top layer, so that the plant can use these nutrients.

NCERT Solutions for Class 8 Science Chapter 1 LAQs

NCERT-Based Long Questions On Crop Production For Class 8

Choose an appropriate agricultural practice from the chart above to fill in the box.

Irrigation→Protection from weeds→ Winnowing

Answer: Irrigation→ Protection from weeds Harvesting! Winnowing

Question 3. Weedicides are chemicals that are sprayed on crop fields to remove weeds

NCERT Solutions for LAQs Crop Management Class 8

The graph shows the production of the wheat crop from each field over two years.

Question 4. Why did the farmer not spray any weedicide on Field 3?
Answer: The farmer did not spray any weedicides on field 3 because, without field 3, the farmer would not be able to tell if the weedicide was effective or not

1. What can the farmer conclude from his tests?

1. Weedicides 1 and 2 were not effective in controlling weeds.
2. Wheat production was better in fields sprayed with weedicide.
3. Crop production decreased in Field 3 as the soil was not fertile.
4. Weedicide was more effective than Weedicide 2 in controlling weeds.

Answer: Wheat production was better in fields sprayed with weedicide.

Crop Production and Management LAQs NCERT Class 8

Question 10. The farmer friend suggested that the farmer should have tested weedicide 1 on the wheat field and weedicide 2 on the mustard field. Will this suggestion help improve the experiment? Explain your answer.
Answer: No, this will not help to improve the experiment. We cannot compare the production of wheat with the production of mustard. To compare the effect of two different weedicides, the crop should remain the same

1. Why are woodlardos generally sprayed on weeds before they start producing flowers and seeds?

1. Woodlard can kill only young weeds.
2. Woodlard can kill the crops if not sprayed early.
3. Tho weeds cannot be killed after they start producing flowers and seeds.
4. The flowers produce more seeds, and the seeds germinate to form more Weeds

Answer: The flowers produce more seeds, and the seeds germinate to form more weeds.

NCERT Solutions For Class 8 Science Chapter 13 Light MCQs

Question 1. In the figure of the human eye, the cornea is represented by the letter

1. A
2. B
3. C
4. D

Answer: 3. C

Question 2. The change in the converging power of an eye lens is caused by the action of

1. Retina
2. Optic Nerve
3. Ciliary Muscle
4. Iris

Answer: 3. Ciliary Muscle

NCERT Class 8 Science Chapter 13 Light MCQs

Question 3. Which of the following statements is correct regarding rods and cones in the human eye?

1. Cones are sensitive to dim light.
2. Cones are sensitive to bright light.
3. Rods are sensitive to bright light.
4. Rods can sense colour.

Answer: 2. Cones are sensitive to bright light.

Question 4. Part of the eye that controls the entrance of light is called

1. Iris
2. Cornea
3. Lens
4. Retina

Answer: 1. Iris

Question 5. A person cannot see distant objects clearly, though they can see nearby objects. He is suffering from a defect of vision called

1. Myopia
2. Hypermetropia
3. Cataract
4. Night Blindness

Answer: 1. Myopia

NCERT Solutions for Class 8 Science Chapter 13 Light

Question 6. The picture shows a candle in front of two plane mirrors joined at their sides.

1. What will increase the number of images formed in the mirrors?
2. Decrease in the size of the object
3. Increase in the size of the mirrors
4. Decrease in the angle between the two mirrors
5. Increase in the distance between the object and the mirrors

Answer: 3. Decrease in the angle between the two mirrors

Question 7. The nature of image formed by a plane mirror is

1. Always virtual
2. Always inverted
3. Always real
4. Real and virtual

Answer: 1. Always virtual

Question 8. The light ray after reflection from a surface is known as

1. Normal ray
2. Refracted ray
3. Reflected rays
4. Incident ray

Answer: 3. Reflected rays

Class 8 Chapter 13 Light Multiple Choice Questions

Question 9. If a single ray is incident on a plane mirror, then how many reflected rays will you observe?

1. Two
2. Zero
3. One
4. Infinite

Answer: 3. One

NCERT Solutions For Class 8 Science Chapter 13 Light SAQs

Question 1. Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room? Explain.
Answer: In the dark room, we cannot sec objects because the objects are visible only when light from an object enters in our eyes. We can see the objects outside the room, if there is light outside. If there is no light outside the room again, we cannot see the object.

Question 2. Differentiate between regular and diffuse reflection. Does diffused reflection mean the failure of the laws of reflection?
Answer: Differences between regular and diffuse reflection are

No, the diffused reflection does not mean the failure of the laws of reflection.

NCERT Class 8 Science Chapter 13 Light Solutions

Question 3. Mention against each of the following whether regular or diffused reflection will take place when a beam of light strikes. Justify your answer in each case.

1) Polished wooden table

Answer: Polished wooden table As the surface is smooth, so there is a regular reflection through it.

2) Chalk powder

Answer: Chalk powder Since, the surface is not smooth or it is uneven, thus there is a diffused reflection through it.

3) Cardboard surface

Answer: Cardboard surface As its surface is uneven, so it will produce a diffused reflection.

4) Marble floor with water spread over it

Answer: Marble floor with water spread over it As marble floor itselfis very smooth, besides this there is a layer of water on it which makes the surface regular for reflection.

NCERT Solutions for Class 8 Science Chapter 13 Light

5) Mirror

Answer: Mirror Since, the surface of mirror is smooth, thus it will produce a regular refelection.

6) Piece of paper
Answer: Piece of paper Since, the surface is uneven, thus It will produce a diffused reflection.

Question 4. State the laws of reflection.
Answer: There are two laws of reflection as below

1. The angle of incidence is equal to the angle of reflection.
2. Incident ray, reflected ray and the normal drawn at the point of incidence to the reflecting surface, all lie in the same plane.

Question 8. Gurmlt wnntod to porform nn activity uxlntf a lavrr torch. Horo, toochor advised her not to do so. Can you explain tho basis of tho tonchor’s advise?
Answer: Laser light comes from a very small hole and the lern of the laser light Is also very small, so the light will penetrate into one part of the eye and it can Injure the retina, whereas the normal torch spreads out the light which does not cause any harm to our eyes. So, the beam of laser light should not be used to perform an activity.

Question 9. Explain how you can take care of your eyes?
Answer: We can take care of our eyes in the following manner

1. If advised, use suitable spectacles.
2. Too little or too much light is bad for eyes. Insufficient light can cause eye strain and headache.
3. Too much light like that of the sun, a powerful lamp or a laser torch can injure the retina.
4. Wash the eyes frequently with clean water.
5. Always read at normal distance for vision.
6. Never rub your eyes.

NCERT Solutions for Light Chapter 13 Class 8

Question 10. What is the angle of incidence of a ray, if the reflected ray is at an angle of 90° to the incident ray?

Answer: We know that, the angle of incidence is equal to the angle of reflection and the reflected ray is at an angle of 90° to the incident ray.

Zi=Zr = 45°

Question 11. How many images of a candle will be formed, if it is placed between two parallel plane mirrors separated by 40 cm?

Answer: Infinite number of images will be formed due to multiple reflections of light.

Question 12. Two mirrors moot at right angles. A ray of light is Incident on one at an angle of 30* as shown In figure. Draw the reflected ray from the second mirror.

Answer: The diagram will be as follows

NCERT Solutions For Class 8 Science Chapter 1 Crop Management Short Answer Questions

Question 1. Chemical substances are added to the soil. How do they differ from manure based on their formation?
Answer: Fertilisers are chemical substances that have a particular plant nutrient in concentrated form. They differ from manure based on formation, as these are produced in factories, while manure can be prepared by the farmer himself on the field.

CBSE Class 8 Science Chapter 1 Short Answer Exam Questions

Question 2. Write the functions of

1. Leveller
2. Hoe
3. Combine
4. Thresher

NCERT Class 8 Science Chapter 1 Crop Management Solutions

Question 3. Despite favourable climatic conditions, n farmer’s crop failed to give a good yield. Give the possible reasons for this.
Answer: If, despite favourable climatic conditions, the farmer’s crop failed to give a good yield, the possibilities may be

1. He did not use good-quality and healthy seeds.
2. His field was not well irrigated.
3. Manures/fertilisers were not timely and proper applied
4. Weeds were not removed
5. Seeds were not sown at an appropriate distance
6. The soil was not ploughed and levelled properly

Question 4. Name the principle followed lot huge huge-scale renting of farm animals. What facilities me provided to form animals?
Answer:

1. The practice of rearing farm animals on a large scale is called animal husbandry.
2. This practice is used to increase the number of livestock animals such as pigs. buffaloes, horses, sheep, etc.
3. In animal husbandry, animals are provided with the following facilities.
4. Proper food and water on time.
5. Appropriate shelter.
6. Have medical access.
7. Safe disposal of animal excreta.

NCERT Class 8 Science Chapter 1 Crop Production LAQs with Answers

Question 5. Give two examples of each

1. Kharif crop
2. Rabi crop

Answer:

1. Soya bean and groundnut are two examples of kharif crops
2. Rea and mustard are two examples of Rabi crops.

NCERT Solutions for Crop Management Chapter 1

Question 6. Write a paragraph in your own words on one of the following

1. Preparation of soil
2. Sowing
3. Weeding
4. Threshing

Answer:

1. Preparation of soil is the first step before sowing he crop. In this, the soil is ploughed to loosen it and make it aerated, which allows the roots to breathe easily.
2. This also helps in the growth of earthworms and microbes in the soil that further turn and loosen the soil.
3. The process of loosening and turning of soil is called tilling or ploughing and is followed by levelling and manuring.
4. Sowing is the process of planting seeds in the soil to grow crops. Traditionally, funnel-like tools were used for sowing. But nowadays, seeds are sown by a seed drill. It sows the seeds at regular intervals in the soil.
5. Weeding is the removal of weeds from the field. Weeding is an essential process as weeds are harmful for the growth of crops because they compete with the crop plants for water, nutrients, space, and light.

NCERT Solutions for Class 8 Science Crop Management

Threshing: The process in which the grain seeds are separated from chaff is called threshing. This is carried out with the help ofa machine called a combine, which is a combination of a harvester and a thresher.

Short Answer Solutions for Class 8 Science Chapter 1 SAQs

Question 7. If wheat is sown in the Kharif season, what would happen? Discuss.
Answer: The seeds of wheat need a low temperature and less humidity to grow. If they are sown in the Kharif (i.e., rainy season), the seeds would get destroyed due to excess water and would not grow.

NCERT Solutions For Class 8 Science Chapter 1 Crop Management VSAQs

Question 1. Give names of the two tradional methods and two modern methods of irrigation of two tmdltlonnl methods and two modorn methods of Irrigation
Answer: Traditional methods of Irrigation are ditch and moat, modern methods of irrigation are sprinkler systems mid drip systems.

Question 2. Pumps are often used in agriculture. Give it to the user.
Answer: Pumps are commonly used to draw water from a water source and distribute it to fields through the irrigation system.

NCERT Solutions for Crop Management Chapter 1

Question 3. Drip Irrigation is considered advantageous over other methods of Irrigation. Do you agree? Explain.
Answer: Yes, in the drip irrigation method, water is released drop by drop near the roots of plants. It is thus considered advantageous over other methods as there is no wastage of water, and it is also economical.

Question 4. Some grass is growing in a wheat field. What will it be known as?
Answer: Grass growing in a wheat field is unwanted, thus it will be known as a weed.

Question 5. Name the tool used for manual harvesting.
Answer: Sickle is used for manual harvesting. It is hand handheld tool with a curved blade.

NCERT Class 8 Science Chapter 1 Crop Management Solutions

VSAQ Solutions for Class 8 Science Chapter 1 Crop Management

Question 6. Define animal husbandry. Write the names of some food materials provided by animals.
Answer: The process of rearing animals by providing them proper food, shelter, and care is called animal husbandry. Some food materials provided by animals are eggs, milk, meat, honey, etc.

NCERT Solutions for Class 8 Science Crop Management

Question 7. Fish are considered good for health. Give a reason.
Answer: Pishes are good for health because they are highly nutritious and rich in vitamin A and vitamin C. They are an important source of animal food in coastal areas.

NCERT Solutions For Class 8 Science Chapter 8 Force And Pressure LAQs

Question 1. In walking, the pressure on the ground is greater than that in standing on the ground. Explain this statement.

Answer: When a person is walking on the ground, at one time, one foot is only on the ground. Therefore, the entire weight of a man falls on a smaller area of the ground, which results in a large pressure on the ground. While in another case, if the man is standing on the ground, then both his feet are on the ground. It causes the force of weight of a man to fall on a larger area of ground and results in less pressure on the ground.

NCERT Solutions for Class 8 Science Force and Pressure

Question 2. Two women are of the same weight. One wears sandals with pointed heels while the other wears sandals with flat soles. Which one would feel more comfortable while walking on a sandy beach? Give reasons for your answer.

Answer:

While walking on a sandy surface, one needs footwear larger area so that the pressure exerted on the ground is minimal. So, in this case, the woman having the sandals with pointed heels will be less comfortable while walking, while the other woman wears sandals with flat soles, feels more comfortable while walking on a sandy beach.

Question 3. It is difficult to cut cloth using a pair of scissors with blunt blades. Explain.
Answer:

It is difficult to cut cloth using a pair of scissors with blunt blades because blunt blades have more area, and due to this, the applied force produces very little pressure. As we know that pressure is inversely proportional to the area of cross-section, so it is difficult to cut cloth with blunt blades

⇒ (\(p=\frac{F}{A}\))

NCERT Solutions for Force and Pressure Chapter 8

Question 4. Observe the vessels A, B, C, and D as shown in the figure carefully.

The volume of water taken in each vessel is as shown. Arrange them in the order of decreasing pressure at the base of each vessel. Explain.
Answer:

1. Pressure at depth due to the liquid column depends upon
2. Gravitational acceleration
3. Density of liquid
4. Height of liquid.

And in this case, gravitational acceleration and density are the same, so the only thing that can change pressure is height.

NCERT Class 8 Science Chapter 8 Force and Pressure Solutions

So, the order of pressure exerted by the fluids A, B, C, and D at the base is given by

PD> PB > PA > PC

Question 5. An archer shoots an arrow in the air horizontally. However, after moving some distance, the arrow falls to the ground. Name the initial force that sets the arrow in motion. Explain why the arrow ultimately falls.
Answer:

The archer shoots an arrow by applying muscular force by stretching the string of the bow. When the string is released, it regains its original position that provides the initial force to set the arrow in motion horizontally. The force of gravity acts on the arrow in the downward direction, and hence the arrow ultimately falls to the ground.