CBSE > Class 09 > Science | CBSE Board | Homework Help

The whole process in which water evaporates and falls on the land as rain and later flows back into the sea via rivers is known as the water-cycle. The organisms get water from and return it to the global water cycle. Plants absorb water from the soil or water reservoir and add it to the air in vapour form by a process called transpiration. Water transpired by trees cools the surrounding air. Animals take water from the water reservoir or with food and return it to the air and vapours by respiration or to the soil by excretion. Mammals also excrete water as sweat which evaporates from the water bodies. Water is added to the environment by the death and decay of organisms. Water vapour formed by transpiration and respiration form clouds and enters global water cycle. Rain adds water to the soil and reservoir for reuse by plants and animals. This completes the water cycle.

0Thank You

ANSWER

If the density of object is 3gm-2 will it float or sink in water

Posted by Siddharth Patel 5 years, 7 months ago

CBSE > Class 09 > Science

0 answers

ANSWER

Which is the most powerful sniper gun in the world

Posted by David Talukdar 5 years, 7 months ago

CBSE > Class 09 > Science

4 answers

Bhola Bhandari 5 years, 7 months ago

CG 15

0Thank You

Dragon Tycoons 5 years, 7 months ago

Awm

2Thank You

Psych Ultra 5 years, 7 months ago

Barrett M82 .50 cal no question the AWM is not even 50 caliber get out of here with PUBG knowledge

1Thank You

Tanishk Ghaloth 5 years, 7 months ago

AWM

2Thank You

ANSWER

what is the work done to increase the velocity of a car from 36kmh to 27 hmm if the mass of the car is 1400kg

Posted by Yashvi Raval 5 years, 7 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 5 years, 7 months ago

Work Done = The Change in Kinetic Energy
= 1/2mv² - 1/2 mu²

The Mass of car = 1500 kg

Intial Velocity = 36 km/h
= 36 × 5 / 18
= 2 × 5
= 10 m/s

Final Velocity = 72 km/hr
= 72 × 5/18
= 5 × 4
= 20 m/s

Work Done = 1/2 mv² - 1/2 mu²
= 1/2 m(v² - u²)
= 1/2 × 1500 ( 20 × 20 - 10 × 10)
= 750 ( 400 - 100)
= 750 × 300
= 225000 J

0Thank You

ANSWER

Why was nnp 2020 indicate by the government

Posted by Preet Bhati 5 years, 7 months ago

CBSE > Class 09 > Science

1 answers

Preet Bhati 5 years, 7 months ago

0Thank You

ANSWER

Give me expanded form of SARS

Posted by Ishika Priyansha 5 years, 7 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 5 years, 7 months ago

Severe acute respiratory syndrome (SARS) : Severe acute respiratory syndrome (SARS) is a serious form of pneumonia. Infection with the SARS virus causes acute respiratory distress (severe breathing difficulty) and sometimes death.

1Thank You

ANSWER

a stone of 1 kg is thrown with a velocity of 20m/s across the frozen surface of a lake and comes to rest after travelling a distance 50m. what is the force of friction between the stone and ice

Posted by Kajal Dogra 5 years, 7 months ago

CBSE > Class 09 > Science

2 answers

Kajal Dogra 5 years, 7 months ago

Ques. Is right

0Thank You

Ayanjyoti Roy 5 years, 7 months ago

the question is wrong. time taken should be mentioned

0Thank You

ANSWER

Different between earth atmosphere and venus

Posted by Sunita Sharma 5 years, 7 months ago

CBSE > Class 09 > Science

1 answers

Ayanjyoti Roy 5 years, 7 months ago

Venus is often named as Earth's twin because both worlds share a similar size, surface composition and have an atmosphere with a complex weather system. The figure on the right compares Venus and Earth spacecraft images. The surface of Venus is shown in orange as radar images while the atmosphere is reproduced on near true colors as it would be seen by the human eye. The upper clouds are brightest in the blue and ultraviolet wavelengths making Venus a white-blue colour planet. Both planets have almost the same size and density and Venus is only a 30% closer to the Sun than Earth. Both share an interesting geological evolution with old volcanoes in Venus and some of them could still be active. One of the biggest misteries of Venus is why its surface is so young on geological time-scales. It is interesting to remark that there is almost no water on Venus' atmosphere. There are many more differences between both planets. Whereas Earth rotates in about 24 hours Venus rotates in the contrary sense (retrograde rotation) in 243 days. The orbital period of Venus is 225 days so that a Venus year takes less than a full day. The combination of these two periods results in the Sun appearing from the West and dissapearing over the East with a day-night cycle of 117 days. The atmosphere of Venus is 90 times more dense than that on Earth and it is made of 96.5% of CO2 and a 3% of nitrogen. This means that both planets have the same amount of Nitrogen on their atmospheres. Surprinsingly the CO2 on Earth is stored on calcite type rocks and if we would convert the CO2 on these rocks into atmospheric CO2 it would amount to the same amount of CO2 that there is on Venus' atmosphere. Because of the denser atmosphere and the chemical composition Venus experiences an inmense green-house effect that raises the temperature over the surface to more than 470ºC. Green-house effect on VenusThe figure on the right illustrates the basics of the greenhouse effect on Venus. Long-wave radiation from the Sun is mainly reflected at the upper cloud deck and partially absorbed by the atmosphere but part of it reaches the surface and heats the lowest atmosphere. The hot surface cools down emitting short-wave radiation that is absorbed and re-emitted by the green-house gases of the atmosphere impeding cooling of the planet and originating the high temperatures at the surface. Figure extracted from here. Clouds are common on Earth but they cover completely Venus' atmosphere. They are made of sulfuric acid droplets at 50-70 km above the surface and at temperatures comparables to Earth's surface temperatures. They are extremely reflective making Venus the most reflecting body in the Solar System.

1Thank You

ANSWER

explane all the low of inertia

Posted by Tanu Parashar 5 years, 7 months ago

CBSE > Class 09 > Science

1 answers

David Talukdar 5 years, 7 months ago

Disapproval

0Thank You

ANSWER

derivation of newton 1,2,3 low of motion graphcally as well as numeracally

Posted by Tanu Parashar 5 years, 7 months ago

CBSE > Class 09 > Science

0 answers

ANSWER

Lipids

Posted by Nihit Singh 5 years, 7 months ago

CBSE > Class 09 > Science

1 answers

Ayanjyoti Roy 5 years, 7 months ago

Lipid is any of a class of organic compounds that are fatty acids or their derivatives and are insoluble in water but soluble in organic solvents. They include many natural oils, waxes, and steroids.

0Thank You

ANSWER

what is health

Posted by Tanu Parashar 5 years, 7 months ago

CBSE > Class 09 > Science

4 answers

Babita Rai 5 years, 7 months ago

It is well beingenoght to function phiscally mantell and socailly

0Thank You

Amrita Kumari 5 years, 7 months ago

Health is the stathe of being we, x

0Thank You

Anas Khan 5 years, 7 months ago

A person physicaly, socially and mentally fit is Healthy

1Thank You

Vansh Gupta 5 years, 7 months ago

Health is the state that free from the disease

0Thank You

ANSWER

who discover the kannad

Posted by Tanu Parashar 5 years, 7 months ago

CBSE > Class 09 > Science

1 answers

David Talukdar 5 years, 7 months ago

You only

0Thank You

ANSWER

Newtons first law?

Posted by Sinan Noushad 5 years, 7 months ago

CBSE > Class 09 > Science

2 answers

Tina ? 5 years, 7 months ago

A body at rest will remain at rest, a body in motion will continue in motion in a straight line with uniform speed , unless it is compelled with an external force an object it is state of rest or of uniform motion

0Thank You

Tanu Parashar 5 years, 7 months ago

when we not applide a external force an objet is not move it can be stationery

0Thank You

ANSWER

What is the mass of 12 mole of copper atom

Posted by Satyam Singh 5 years, 7 months ago

CBSE > Class 09 > Science

0 answers

ANSWER

Which subatomic particli is present in nucleus of an atom

Posted by Bhawana Jewaria 5 years, 7 months ago

CBSE > Class 09 > Science

5 answers

Vedansh Tomar 5 years, 7 months ago

Yes the bohr madol of atom is also say thak the protone and neuton are parasent in neucles but the eloctrone are parsent in out side of neucles in energa lavel

0Thank You

Tanu Parashar 5 years, 7 months ago

in nucleus there is two subatomic partical neutron and proton.where neutron are nutral partical and proton are positively charge partical. both together contitutes the mass number of the atom.and this is also called a bohr's model. the bohr model are also said that proton and neutron are embedd partical

0Thank You

Ashutosh Kumar Tiwari 5 years, 7 months ago

neutron and proton

0Thank You

Spurthi Raghothama 5 years, 7 months ago

There are three subatomic particles which are PROTONS, NEUTRONS and ELECTRONS

1Thank You

Satjinder Dhillon 5 years, 7 months ago

There are two types of sub atomic particles in nucleus, one is neutron and other is proton.

Both together constitutes the mass number of the atom

0Thank You

ANSWER

What is the mass of 0.2 moles of a oxygen

Posted by Madhur Sharma 5 years, 7 months ago

CBSE > Class 09 > Science

4 answers

Arpit Verma 5 years, 7 months ago

0.2 mole of oxygen atoms=0.2 mol*molar mass of oxygen atom=0.2mol*16mol=3.2gm

0Thank You

Ashutosh Kumar Tiwari 5 years, 7 months ago

32/5=6.4g

0Thank You

Satjinder Dhillon 5 years, 7 months ago

1. If it oxygen atom...

Atomic mass = 16 u

Gram atomic mass = 16gm

i.e. 16gm oxygen atoms have 1 mole of atoms

Which means 0.2 moles of atom = 0.2 × 16 gm

= 3.2gms

2. If its oxygen gas(molecule) O₂ then

Molecular mass of O₂= 32 u

Gram molecular mass is 32gm

i.e. 1 mole of O₂ molecules have 32 gm mass

Hence 0.2 moles = 0.2 x 32 gm

i.e. 6.4 gm is the answer

0Thank You

Madhur Sharma 5 years, 7 months ago

2.0f

0Thank You

ANSWER

Which of the following is not the unit of energy

Posted by Isha Bedia 5 years, 7 months ago

CBSE > Class 09 > Science

2 answers

Isha Bedia 5 years, 7 months ago

Options-( a)joul (b) N-m (c)kwh (d)kw

0Thank You

Tanu Parashar 5 years, 7 months ago

meter per second is not the unit of energy.and there is more...

2Thank You

ANSWER

Acceleration due to gravity near the Earth's surface is 9.8 metre per second square and the earth's radius is 6400 km from this data calculate the mass of the earth use any Universal constant it if required

Posted by Satish Pandey 5 years, 7 months ago

CBSE > Class 09 > Science

0 answers

ANSWER

Why do we fall ill ??

Posted by Zoya Choudhary 5 years, 7 months ago

CBSE > Class 09 > Science

2 answers

Tejaswani Singh 5 years, 7 months ago

We fall ill when microbes invades in our body and when our immunity system cannot fight with those microbes, so when it happens our immunity system needs time to recover and between that time when microbes enters in our body till the time our immunity system recovers to fight with those microbes, we fall ill

1Thank You

Abhishek Chaudhary 5 years, 7 months ago

We fall ill causes of diseases

1Thank You

ANSWER

Why do we ill

Posted by Mr Nandan Hacker 5 years, 7 months ago

CBSE > Class 09 > Science

1 answers

Meghna Thapar 5 years, 7 months ago

There are two types of factors that causes diseases – extrinsic factors and intrinsic factors.

The disease causing factors which exist within the human body are called intrinsic factors. Example – malfunctioning of various body parts, hormonal imbalances, genetic disorder, etc.
The disease causing external agents which enter the human body from outside are referred to as extrinsic factors. Example – unbalanced diet, environmental pollutants, etc.

0Thank You

ANSWER

Give me the expanded form of the WHO

Posted by Ishika Priyansha 5 years, 7 months ago

CBSE > Class 09 > Science