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    • Posted by Abhishek Kumar 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Abhishek Kumar 7 years, 2 months ago

    Akansha can you tell me one natural or one man made process

    1Thank You

    Akanksha Kumari? 7 years, 2 months ago

    I think the required processes are: ▪combustion ▪Respiration

    6Thank You

    ANSWER

    • Posted by Sanjay Sharma 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Akanksha Kumari? 7 years, 2 months ago

    We hear sound with the help of our ears. Ear is divided into 3 parts: 1. Inner ear 2. Middle ear 3. Outer ear Firstly, the travelling sound reaches the pinna and the sound get collected there. From pinna it goes to the ear canal and travels through it. Further it passes through Anvil, Stirrup and Hammer. This causes the vibration of ear drum . Then it enters the Cochlea and get transferred to the auditory nerve. The brain reaches the impulse.

    0Thank You

    ANSWER

    • Posted by Jatinder Singh 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Akanksha Kumari? 7 years, 2 months ago

    Work, energy and power is very easy chapter . Work is the product of force and displacement. Energy is the ability to do work. Power is the rate of doing work. Further there are some easy formulas for numericals . Try to solve the numericals and learn the definitions. For better understanding refer to cbse guide revision notes.

    2Thank You

    ANSWER

    • Posted by Bhargav Parate 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Akanksha Kumari? 7 years, 2 months ago

    It's monoatomic.

    3Thank You

    Sayoni Debnath 7 years, 2 months ago

    Monoatomic

    3Thank You

    ANSWER

    • Posted by Manoj Kumar Singh 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Isha Saharan 7 years, 2 months ago

    C2H5OH is formula of sprit

    0Thank You

    Akanksha Kumari? 7 years, 2 months ago

    C2H5OH

    2Thank You

    ANSWER

    • Posted by Saurabh Kumar 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Anshika Prakash 7 years, 2 months ago

    Because millions of years ago they had free existence in the environment but due to many activities, the got combined with the cells to get organised.

    0Thank You

    Sanjay Sharma 7 years, 2 months ago

    Because both are able to make some of their own proteins and ribosomes

    1Thank You

    ANSWER

    • Posted by Pramod Sarode 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Pramod Sarode 7 years, 2 months ago

    A suspension of soil chack powder and fine sand in water

    3Thank You

    ANSWER

    • Posted by Sanjay Sharma 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 3 answers

    Isha Saharan 7 years, 2 months ago

    Used to clean unshaped parts of machines

    0Thank You

    Bhargav Parate 7 years, 2 months ago

    SONAR, medical applications, detecting cracks and defects in a metal block.

    0Thank You

    Vidhi Chauhan 7 years, 2 months ago

    1. Industrial applications of ultrasound a. Ultrasonic cleaning b. To find defects and cracks in metals c. Drilling holes or making cuts of desired shape 2. Medical application of ultrasound a. Echocardiography b. Ultrasonography c. Ultrasound surgery

    2Thank You

    ANSWER

    • Posted by Adada. Sanyasirao 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Akanksha Kumari? 7 years, 2 months ago

    By fractional distillation . Fractional distillation depends on the boiling points of the two liquids.

    3Thank You

    ANSWER

    • Posted by Itika Singhal 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Bhargav Parate 7 years, 2 months ago

    May be we dont know the future

    0Thank You

    ANSWER

    • Posted by Pushpa Kumari 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Geetanshi Bametha 10 C 7 years, 2 months ago

    Stone will reach first. Although both will face equal acceleration of 9.8m/s2 but paper being light weighted will face air resistance too and will reach the ground later on. Hope this helps

    1Thank You

    Harsh Vishwakarma 7 years, 2 months ago

    Stone reach first at ground,because of gravatition

    0Thank You

    ANSWER

    • Posted by Pushpa Kumari 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Arjun Bhatty 7 years, 2 months ago

    Which?

    0Thank You

    ANSWER

    • Posted by Sanjay Sharma 5 years, 11 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Itika Singhal 7 years, 2 months ago

    Echo takes place under some conditions such as time period,distance travelled by sound wave etc. On the other hand, no condition applies on reverberation.

    1Thank You

    ANSWER

    • Posted by Srijayant Panigrahi 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Meghna Thapar 6 years, 1 month ago

    In the atmosphere oxygen is found in two forms:

    i. Diatomic molecule having two oxygen atoms (O2) and found in the lower regions of the atmosphere.

    ii. Triatomic molecule having three oxygen atoms (O3) also called as ozone and is found in the upper regions of the atmosphere.

    Unlike the normal diatomic molecule of oxygen, ozone is poisonous but it absorbs harmful radiations from the Sun and prevents them from reaching the surface of the Earth. Recently it was discovered that this ozone layer was getting depleted.

    Ozone depletion is caused by certain chemicals called ozone depleting substances. They include chlorofluoro carbons, methyl bromide, nitrogen oxides and chlorine.

    Effects of ozone depletion:

    (i) Skin cancer.

    (ii) Damage of eyes.

    (iii) Damage of immune system.

    (iv) Decreased crop yields.

    0Thank You

    ANSWER

    • Posted by Sushil Singh 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 0 answers
    ANSWER

    • Posted by Sim Pate 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 0 answers
    ANSWER

    • Posted by Divya Singhal 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Akanksha Kumari? 7 years, 2 months ago

    Inflammation is body's response to an injury. It is a short term response with localized effects.

    1Thank You

    ANSWER

    • Posted by Sanjay Sharma 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Yogita Ingle 7 years, 2 months ago

    Preventive measures ensure that the crop plants are protected from the harmful biotic factors (such as diseases, weeds and insects) and abiotic factors (such as drought and salinity). Biotic and abiotic factors can cause huge losses of food grains and need proper treatment to control them. So it is better to take preventive measures and avoid loss in crop plant production.
    Using chemical control methods is not advisable since their use creates problems. They are poisonous to plant and animal species and cause environmental pollution. They reach human beings through the food chain. On the other hand, biological control methods are safe for plants, animals, humans and the environment in general.
    Hence, preventive measures & biological control methods are preferred for protecting crops.

    1Thank You

    Dharmendra Giri 7 years, 2 months ago

    Weedicide harvesting threshing winnowing storage method be preferred for protecting crops

    2Thank You

    ANSWER

    • Posted by Vineet Kumar 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Gaurav Seth 7 years, 2 months ago

    Mari culture is a specialized branch of aquaculture involving the cultivation of marine organisms for food and other products in the open ocean, an enclosed section of the ocean, or in tanks, ponds or raceways which are filled with seawater.  the cultivation of fish or other marine life for food.

    0Thank You

    ANSWER

    • Posted by Adarsh Priyadarshi 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Geetanshi Bametha 10 C 7 years, 2 months ago

    Our cells keep on dividing and after division they take up specific functions. Division of labour this process is known as.

    0Thank You

    ANSWER

    • Posted by City Susant 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 4 answers

    Aastha Singhal 7 years, 2 months ago

    It is third law of motion it state that for every action there is equal and opposite reaction as birds fly perch to perch each beat of its wing pushes the air which in turn pushes against the box and also sucks the ceiling slightly

    0Thank You

    Itika Singhal 7 years, 2 months ago

    First law ! How? Will you please explain?

    0Thank You

    Soni Bano 7 years, 2 months ago

    First law of motion

    1Thank You

    Piyush Kumar 7 years, 2 months ago

    1st law of motion

    2Thank You

    ANSWER

    • Posted by Harsh Rozra 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Sanjay Sharma 7 years, 2 months ago

    When water vapours in the atmosphere pass from the cold area then water vapour are in the form of water droplets . These droplets cloud formed

    0Thank You

    Harsha Lamba 7 years, 2 months ago

    U dont know

    1Thank You

    ANSWER

    • Posted by Prithvi S 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 4 answers

    Jagannath Arpit Das 7 years, 2 months ago

    Sound is a mechanical wave. All mechanical wave require a medeum to travel . So sound cant travel through vaccum

    0Thank You

    Sandhya Singh 7 years, 2 months ago

    We know that vacuum is an empty place no matter is there and sound need a medium for travel that's why sound can't travel in vacuum....

    0Thank You

    Gaurav Seth 7 years, 2 months ago

    Vacuum is empty space, devoid of any mater, particles and even air. Vacuum is a state which is referred to being complete emptiness. For example - the outer space is a near perfect vacuum.

    Sound is a mechanical wave and mechanical waves are propagated by the oscillation of molecules in a medium like, air, water or gas. There are no molecules in the vacuum to produce oscillations. So sound cannot travel through vacuum.

    0Thank You

    Akanksha Kumari? 7 years, 2 months ago

    Sound doesn't travel through vacuums because in vacuums there are no matter or particles to vibrate and we know that sound is produced by the vibration of particles.

    0Thank You

    ANSWER

    • Posted by Neha Panwar 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Yogita Ingle 7 years, 2 months ago

    The phenomenon of repetition of a sound due to its reflection from the surface of a large obstacle is termed as echo.
    For example, when a loud sound is produced in an empty hall, the same sound is heard again after some time. 
    To produce an echo, the conditions required a are: 
    (i) There should be sufficient time gap between original and reflected sounds. So, if we want to hear distinct echo, the reflected sound must reach the ear 0.1 s after the direct original sound.
    (ii) The distance between the source of sound and the obstacle should be sufficient. An echo will be heard distinctly if the minimum distance between the source of sound and the obstacle is 34.4/2 = 17.2 m.
    (iii) Nature of the obstacle plays an important role. For the formation of echo, the reflecting surface must be rigid such as a building, hill or a cliff.
    (iv) Size of the obstacle should be quite large for the echoes to be heard.

    2Thank You

    Jyoti Sharma 7 years, 2 months ago

    Reflection of multiple sound is called an echo .The condition to hear an echo is : the length should be 17.2 m and the sound limit be 0.01 second

    3Thank You

    ANSWER

    • Posted by Neha Panwar 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Yogita Ingle 7 years, 2 months ago

    1. Average speed is a scalar quantity, while average velocity is a vector quantity.

    2. Average speed takes into account the total distance traveled, while average velocity is concerned with the displacement between two points.

    3. In average velocity, direction is expressed.

    4. More often than not, the values will differ, with average speed usually having the higher value.

    5. Average velocity can be equal to zero, even when the body has completed a traveling motion, as long as the destination point is back at the origin. In this case, the average speed will always have a greater value.

    1Thank You

    Akanksha Kumari? 7 years, 2 months ago

    Average speed- it refers to the total distance travelled divided by the total time taken to cover that distance. Average velocity - it refers to the total displacement divided by the total time.

    2Thank You

    ANSWER

    • Posted by Kavya Sharma 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Yash Saluja 7 years, 2 months ago

    2:3

    2Thank You

    Priyadarsini Hotta 7 years, 2 months ago

    2:3

    2Thank You

    ANSWER

    • Posted by Priyanshu Tiwari 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 1 answers

    Nupur Goswami 7 years, 2 months ago

    No we can't because hydrosphere,atmosphere and lithosphere interact together to make the biosphere but hydrosphere is not considered as atmosphere.another reason is that atmosphere is acts as a protective blanket of the earth and is combined with many other layers while hydrosphere just comprises the total water present on the earth which is about 75 percent. Hence proved.

    1Thank You

    ANSWER

    • Posted by Shruti Rana 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Nupur Goswami 7 years, 2 months ago

    Because it is that atom among the others similar to it which has the capacity of lsing and gaining electrons both.that is why.

    0Thank You

    Yogita Ingle 7 years, 2 months ago

    The number of electrons gained, lost, or shared by an atom to complete its octet is called the combining capacity or valency of that atom Phosphorous on using its 3 electrons can form PCl3 . If it will use its 5 electrons then it can form PCl5. Hence it can show both 3,and 5 valency.

    3Thank You

    ANSWER

    • Posted by Vivek Mishra 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 0 answers
    ANSWER

    • Posted by Anchal Upadhyay 7 years, 2 months ago

    CBSE > Class 09 > Science
    • 2 answers

    Nupur Goswami 7 years, 2 months ago

    A colloidal solutions appears to be homogenous but is actually a heterogenous one. 1. it appears to be homogenous because its particle are bigger than the size of the particles of true solution but are very small than the size of that of a suspension. 2. as the size of its particles are bigger than the size of true solution it can show tyndall effect , also has a non uniform composition and is quite stable.therefore it actually is a heterogenous one. Hence proved

    0Thank You

    Prathmesh Kadam 7 years, 2 months ago

    Colloid is a hetrogenous mixture because particals can be seprated by filteration 2 scater beam of light

    1Thank You

    ANSWER

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