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If according to third law of motion, action and reaction forces are always equal in magnitude then why does a plastic bal travel more distance after colliding with an iron sphere? Explain

Posted by Shiv Dayal 6 years, 2 months ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 2 months ago

Mass of ball , m₁ = 0.5 kg Velocity of ball , v₁ = 5 m/s Mass of another ball , m₂ = 1 kg Let velocity of another ball = v₂ m/s Using law of conservation of momentum , 0.5 x 5 + 1 x v₂ = 0 v₂ = - 2.5 m/s Therefore , the velocity of another ball is 2.5 m/s opposite to the direction of motion of first ball.

ANSWER

From where does water droplets come on mirror when we exhale air on it

Posted by Ramesh Kumar 6 years, 2 months ago

CBSE > Class 07 > Science

2 answers

Yogesh Shinde 6 years, 2 months ago

Because of the moisture present in our mouth

Anjana Kumari 6 years, 2 months ago

The air from our mouth come have moisture in it. When it touches the glass the moisture get condensed and we see water droplets on it

ANSWER

How the respiration of plants take place?

Posted by Joy Tv 6 years, 2 months ago

CBSE > Class 07 > Science

1 answers

Sia ? 6 years, 2 months ago

There modes for the exchange of gases in plants are as follows:

Plants respire through the tiny pores on the surface of their leaves called stomata. Oxygen enters the plant, while carbon dioxide leaves the plant through these pores. This exchange of gases occurs through the process of diffusion.
Plants do not get all of the oxygen they need for respiration from their stomata. They also absorb oxygen from their roots. This is why plants need well-aerated soil to grow properly. Waterlogged or compacted soil can kill plants by drowning or suffocating them.
In woody stems, exchange of gases occurs through lenticels in the bark.

ANSWER

We use symbols to draw a circuit

Posted by Amaan Ahmed 6 years, 2 months ago

CBSE > Class 07 > Science

2 answers

Amaan Ahmed 6 years, 2 months ago

How

Aryan Gaurkhede 6 years, 2 months ago

Yes, we do this

ANSWER

What is fermintation

Posted by Zaara Khan 6 years, 2 months ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 2 months ago

Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes ------------------------------------------------------------------------------- Any energy-releasing metabolic process that takes place only under anaerobic conditions (becoming more scientific). ------------------------------------------------------------------------------- Any metabolic process that releases energy from a sugar or other organic molecule, does not require oxygen or an electron transport system, and uses an organic molecule as the final electron acceptor. Fermentation comes from the Latin word fermentare, meaning “to leaven.”

ANSWER

Alveolus

Posted by Jayanth Shri Karthik I 6 years, 2 months ago

CBSE > Class 07 > Science

2 answers

.. ... 6 years, 2 months ago

An alveolus (plural: alveoli) is a word used in anatomy for hollow cavities, which are empty areas within a body. Although there are many different types of alveoli in the body, the word alveoli is usually used to talk about small air sacs in the lungs of mammals. These are also called pulmonary alveoli. These alveoli are located at the ends of the air passageways in the lungs. They have very thin (one cell thick), wet walls and are surrounded with a network of small blood vessels, or capillaries. This allows gases to diffuse, or move across, the surface of the alveolus.

Shrin .G 6 years, 2 months ago

How dose a snail respairat

ANSWER

When air is blown over paper strip, it lifts up. Why and how? Explain it briefly.

Posted by Arya Anupam 6 years, 2 months ago

CBSE > Class 07 > Science

1 answers

Anjana Kumari 6 years, 2 months ago

When air is blown over a paper strip. It lift up because of air pressure. We know that air moves from high pressure to low presure the air above is high pressure and down of paper the presure is low so the air pressure pushes the paper up and the paper lift up

ANSWER

Who is the giant

Posted by Thakshari Chethas 6 years, 2 months ago

CBSE > Class 07 > Science

3 answers

Aakash Thanapati 6 years, 2 months ago

Gaint means a big manster

Shrin .G 6 years, 2 months ago

Gaint is an a troop in coc

Jayanth Shri Karthik I 6 years, 2 months ago

Monster

ANSWER

Give precautions during tornado

Posted by Shanjutha Shanjutha 6 years, 2 months ago

CBSE > Class 07 > Science

1 answers

Gaurav Seth 6 years, 2 months ago

Qick communication to government agencies, fishermen, ports to make necessary arrangements and minimize destruction.
As an individual, when cyclone or a tornado strikes, take shelter under tables, bow down and protect head and neck using arms.
Keep away from water in cyclone-hit areas as the water might be contaminated.
Stay inside houses.
Should not ignore warnings from meteorological department.
Should have all emergency numbers.
Avoid driving on roads full of water as the roads might be damaged or the vehicle may get stuck with water going inside the machinery.
Cyclone/Tornado can cause damage to electric poles and it may cause short circuit and electric shocks.
Cooperate and help others.

ANSWER

Explain the process of breathing in a tree

Posted by Anjana Kumari 6 years, 2 months ago

CBSE > Class 07 > Science

1 answers

Vaheeda Pathakadapa 6 years, 2 months ago

The process of oxygen

ANSWER

Burning of magnesium ribbon

Posted by Rashmi Khandelwal 6 years, 2 months ago

CBSE > Class 07 > Science

3 answers

Yogesh Shinde 6 years, 2 months ago

It turn to magnesium hydroxide

€Kabir£ Patharwat 6 years, 2 months ago

It burnt with brilliant white light & Gives powdery ash RECAN- MG+O2>MGO ( MAGENESIUM OXIDE

Anjana Kumari 6 years, 2 months ago

Get a price of thin strip or ribbon. Clean it tip with sandpaper. Bring the strip mear a flame. It burn with brilliant white light When it is completely burn it give a powdwey ash. You mix the ash with water and check with litmus. It turns red to blue the litmus so the solution is basic

ANSWER

What is tomorrows timing

Posted by Kshanada????? Barde 6 years, 2 months ago

CBSE > Class 07 > Science

2 answers

Tanya Gupta 6 years, 2 months ago

Which timing are you talking about

Anjana Kumari 6 years, 2 months ago

Which timing

ANSWER

What is alkali and write one example

Posted by Ruhan Yadav 6 years, 2 months ago

CBSE > Class 07 > Science

2 answers

Satadru Sengupta 6 years, 2 months ago

Alkali are the bases soluble in water. For example- Sodium hydroxide, Potassium hydroxide

Rashmi Khandelwal 6 years, 2 months ago

Alkali are the bases which are soluble in water

ANSWER

Explain the following 1. Ant bite 2. Soil treatment 3. Factory waste

Posted by Anjana Kumari 6 years, 2 months ago

CBSE > Class 07 > Science

2 answers

Ridhi Mahajan 6 years, 2 months ago

Answer of 3rd part : Factory Waste := factory waste contains both acid and basic substance show it should be decomposed instead of throwing it in the river and burning it

Yogesh Shinde 6 years, 2 months ago

Ant bite contain formic acid if we rub baking soda on it it will nutrilise

ANSWER

The examples of salts

Posted by Suryakant Kemdarne 6 years, 2 months ago

CBSE > Class 07 > Science

3 answers

Vikash Kumar 6 years, 2 months ago

Sodiumchloride

Satadru Sengupta 6 years, 2 months ago

Calcium carbonate, Sodium carbonate, Sodium bicarbonate, Silver nitrate, Ammonium nitrate, Potash alum, Sodium chloride.

Parveen Kumar 6 years, 2 months ago

Sodium hydroxide Ammoniam sulphate Sodium carbonate

ANSWER

Xxx

Posted by Santosh Kumar 6 years, 2 months ago

CBSE > Class 07 > Science

2 answers

Mohd. Maroof 6 years, 2 months ago

I explain . Are you want that i explain you

Anjana Kumari 6 years, 2 months ago

Can you explain what is Xxx

ANSWER

Is warer holding capacity poor in clayey soil? If not , then why in ch9 solutions of class 7 in 'My CBSE Guide' Q.6 in difference is written that,"It has poor water holding capacity"?

Posted by Soham Rasaniya 6 years, 2 months ago

CBSE > Class 07 > Science

2 answers

Yogesh Shinde 6 years, 2 months ago

These two sentence mean is same

Anjana Kumari 6 years, 2 months ago

What the heck. It doesn't have poor water holding capacity

ANSWER

My exams are near and I am not able to learn diagrams in Science. How should I learn diagrams so that I can do well in exams ?

Posted by Tanya Gupta 6 years, 2 months ago

CBSE > Class 07 > Science

7 answers

Tanya Gupta 6 years, 2 months ago

Thank you

Yogesh Shinde 6 years, 2 months ago

First see it properly and pratice it twice

€Kabir£ Patharwat 6 years, 2 months ago

Look that diagram carefully & draw that diagram many time in rough book . I think in ur exam life history of silkmoth will come or Layers of soil will come

Saniya Shah 6 years, 2 months ago

You also take diagram as shapes and aeros you do well

Tanya Gupta 6 years, 2 months ago

Thank you Anjana and Vaheeda

Vaheeda Pathakadapa 6 years, 2 months ago

By practice more days

Anjana Kumari 6 years, 2 months ago

You practice it and some time trace it from text book you can do better

ANSWER

Steel pans are provided with copper bottoms. Why?

Posted by Arya Anupam 6 years, 2 months ago

CBSE > Class 07 > Science

1 answers

Anjana Kumari 6 years, 2 months ago

Because copper is a good conductor of heat and it spread the heat equally on the pan take a example that if we take a iron rod heat it at one side and put the other end in water the water won't boil but do the same thing in copper rod the water get heated. Thank you

ANSWER

When air is blown over apaper strip, it lifts up. Why?

Posted by Arya Anupam 6 years, 2 months ago

CBSE > Class 07 > Science

2 answers

Amita Rasaniya 6 years, 2 months ago

Due to following statement "Aur Exerts Pressure"

Anjana Kumari 6 years, 2 months ago

Because of air pressure

ANSWER

With the help of two activities show that air exert pressure.

Posted by Arya Anupam 6 years, 2 months ago

CBSE > Class 07 > Science

2 answers

Vaheeda Pathakadapa 6 years, 2 months ago

1activity _ take 20cm strip of paper and keep in side your lip blow it

Anjana Kumari 6 years, 2 months ago

The first activity is - 1. When we fill air in a balloon it inflatens due to pressure exerted by air 2.when we hang a banner in a place of moving fast air. It tears due to Air pressure. Thanks

ANSWER

Suggest any activity for seperation of substances

Posted by Shahista Kazi 6 years, 2 months ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 2 months ago

Handpicking is one of the simplest techniques used for separating substances. E.g. removal of husk or stone particles from grain ----------------------------------------------------- Winnowing is used to separate substances of different weights in a mixture by wind or blowing of air. ---------- Sieving is used to separate a mixture of different sized particles. ------------------------ Sedimentation technique can be used to separate heavy particles from lighter ones by putting the mixture in water. Heavy particles settle to the bottom. Lighter particles float. The water along with the lighter particles can then be removed by decantation ------------------ Evaporation can be used to separate solids dissolved in a liquid.

ANSWER

Short note on migratory birds

Posted by Savitha S 6 years, 2 months ago

CBSE > Class 07 > Science

2 answers

Vaheeda Pathakadapa 6 years, 2 months ago

Migratory birds escape from bird century for their climatic conditions

Anjana Kumari 6 years, 2 months ago

Migratory birds escape harsh and cold conditions. It movrs to the region of mild climate

ANSWER

FULL form of CFL , MCB BIS

Posted by Sai Kiran Mahanty 6 years, 2 months ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 2 months ago

compact fluorescent light A compact fluorescent lamp (CFL), also called compact fluorescent light. ------------------------------------------ The full form of MCB is Miniature Circuit Breaker ------------------------------------------------------------------------------ BIS stands for Bureau of Indian Standards.

ANSWER

Distance time graph for non uniform motion

Posted by Saransh Modi 6 years, 2 months ago

CBSE > Class 07 > Science

1 answers

Meghna Thapar 5 years, 10 months ago

Distance – Time Graphs:

The change in the position of an object with time can be represented on the distance-time graph. In this graph, time is taken along the x–axis and distance is taken along the y-axis.

Distance-time graphs can be employed under various conditions where objects move with uniform speed, non-uniform speed, remain at rest etc.

When an object travels equal distances in equal intervals of time, it moves with uniform speed. This shows that the distance travelled by the object is directly proportional to time taken. Thus, for uniform speed, a graph of distance travelled against time is a straight line whereas for non-uniform speed it is a curved line.

ANSWER

Which device is used to measure?

Posted by Krishna Moorthi 6 years, 2 months ago

CBSE > Class 07 > Science

5 answers

Jayanth Shri Karthik I 6 years, 2 months ago

Hygrometer is to measure humidity

Vaheeda Pathakadapa 6 years, 2 months ago

Anemometer is used to measure wind

R Mishra Mishra 6 years, 2 months ago

Anemometer is also used to measure direction of wind

Anshu . 6 years, 2 months ago

Temperature= thermometer Air pressure= Aneroid barometer

.. ... 6 years, 2 months ago

•Accelerometer, physical, acceleration •Ammeter, electrical, amperage, current •Anemometer, wind speed •Caliper, distance •Calorimeter, heat •DNA sequencer, molecular biology •Dynamometer, torque/force •Electrometer, electric charge, potential difference •Electroscope, electric charge •Electrostatic analyzer, kinetic energy of charged particles •Ellipsometer, optical refractive indices •Eudiometer, gas volume •Gravimeter gravity

ANSWER

On a single day the at any one place may change significantly

Posted by Priyanshu Dwivedi 6 years, 2 months ago

CBSE > Class 07 > Science

1 answers

Arya Anupam 6 years, 2 months ago

Weather

ANSWER

What is a matter of paper

Posted by Shalu Aggarwal 6 years, 2 months ago

CBSE > Class 07 > Science

1 answers

Yogita Ingle 6 years, 2 months ago

Anything that has mass and occupies a space is called matter. The matter is made up of very tiny particles and these particles are so small that we cannot see them with naked eyes. It has been observed that matter exists in nature in different forms. Some substances are rigid and have a fixed shape like wood and stone; some substances can flow and take the shape of their container like water, while there are forms of matter that do not have definite shape or size such as air.

ANSWER

CBSE last year exam papers of science 2018 -19 class 7th

Posted by S S Randhawa 6 years, 2 months ago

CBSE > Class 07 > Science

2 answers

Saniya Shah 6 years, 2 months ago

You see in ncert apps

Vaheeda Pathakadapa 6 years, 2 months ago

Noo

ANSWER

What is s e x

Posted by Swagboy Sumit 6 years, 2 months ago

CBSE > Class 07 > Science

0 answers

ANSWER

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