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

Ask questions which are clear, concise and easy to understand.

Ask Question

Write three difference between infectious and non infectious diseases

Posted by Sandhya Saini 7 years, 1 month ago

3 answers

INFECTIOUS DISEASES:- they are caused by pythogens. 2) it can pass from diseased person to healthy person 3) transmission of infection occurs through direct contect NON- INFECIOUS DISEASES:- 1) they are caused by factors of other than pythogens. 2) it cannot pass from one person to another. 3) transmition is absent except for hereditary disease where it occurs from parent to off spring

0Thank You

Yogita Ingle 7 years, 1 month ago

Infectious diseases	Non-infectious disease
1. Caused due to attack of pathogens	1. Caused by factors other than pathogens
2. Caused due to extrinsic factors	2. Caused due to intrinsic factors
3. Transmitted from one person to another	3. Do not get transmitted from one person to another
4. Transmission of diseases occurs through direct contact or some medium (air, water, vectors)	4. Transmission in case of hereditary diseases is from parent to offspring
5. Community hygiene can reduce the occurrence of these diseases	5. Community hygiene is ineffective in reducing the occurrence of these diseases
E.g. Cholera, Malaria	E.g. Diabetes, Goitre

2Thank You

Rida Fatima Ansari 7 years, 1 month ago

Infectious disease can transfer from infected person to healthy person but in the case of non infectious disease this is not happen Infectious disease is a cause of external factors and non infectious is a cause of internal factors Infectious disease are cholera, aids etc. Non infectious disease are khwashiorkar , etc..

0Thank You

ANSWER

Define sublimation evaporation scratch python and how to derive all three equations of motion

Posted by Mamta Rathi 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Meghna Thapar 6 years, 1 month ago

Sublimation:

Principle: This method is based on the sublimable and non-sublimable nature of solids.

Technique: The mixture of a sublimable and non-sublimable substance is heated in an evaporating dish covered with an inverted funnel. This results in the evaporation of the sublimable solid and further condensation on the side of the funnel, leaving the non-sublimable solid behind in the dish. Example: Separation of ammonium chloride and sodium chloride in the laboratory; Separation of iodine and sodium chloride in the laboratory.

Evaporation:

Principle: This method is based on the evaporation of the liquid component in a soluble solid-liquid mixture.

Technique: The mixture is heated such that the liquid component evaporates and the solid remains behind.

Observation: Ink is a mixture of a dye in water. Thus, we can separate the volatile component (solvent) from its non-volatile solute by the method of evaporation.

0Thank You

ANSWER

What is alternation of generation

Posted by Suraj Chougule 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Suraj Chougule 6 years, 4 months ago

Shreya sharma kaha ho

1Thank You

ANSWER

Why black colour absorbs more heat than white colour

Posted by Manu Guttal 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Meghna Thapar 6 years, 1 month ago

A black object absorbs all wavelengths of light and converts them into heat, so the object gets warm. A white object reflects all wavelengths of light, so the light is not converted into heat and the temperature of the object does not increase.

0Thank You

ANSWER

Some people have fair complexion and some have Dark complexion. What is the reason for this?

Posted by Jatin Bumika Jindal 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Aditya Raghav 7 years, 1 month ago

Skin colour is due primarily to the presence of a pigment called melanin. Which is controlled by genes. both dark and light complexioned people have melanin.

0Thank You

ANSWER

Comment on Rutherford 's model

Posted by Nandini Singh Rajpoot 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Aditya Raghav 7 years, 1 month ago

He performs the experiment again & again to verify that atom has a positively charged nucleus.

1Thank You

ANSWER

Some one please tell me Which law of motion applies on flying of bird? I have asked this question before. But no one answered. .

Posted by Itika Singhal 7 years, 1 month ago

CBSE > Class 09 > Science

6 answers

Akanksha Kumari 7 years, 1 month ago

newton's third low of motion

1Thank You

Akanksha Kumari 7 years, 1 month ago

Newton's third low of motion bird fly

0Thank You

Aditya Raghav 7 years, 1 month ago

Newtons first law of motion , inertia because in this case the external force applied by the movement of wings

1Thank You

Anchal Bharti? 7 years, 1 month ago

No motion

1Thank You

Sandhya Singh 7 years, 1 month ago

First law of motion bcz if a body in rest will remain in rest or the body in motion will remain in motion until an external force apply on it.

2Thank You

Skyros (Shubham Kumar) 7 years, 1 month ago

Third law

1Thank You

ANSWER

In what condition 3 equation is use

Posted by Abhishek Verma 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Lakshita Bookworm 7 years, 1 month ago

Mostly when we've to find time. Or we can say when time is not given

2Thank You

ANSWER

Under what condition we use the 3 equation of motion

Posted by Sachin Singh 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Akanksha Kumari 7 years, 1 month ago

if you have to find distance,without time than use 3equation of motion

2Thank You

ANSWER

Two reactants kept in a beaker as aqueous solution weigh 200 g altogether. Calculate the total mass of products formed if beaker weigh 100 g

Posted by Jyoti Sharma 7 years, 1 month ago

CBSE > Class 09 > Science

0 answers

ANSWER

Derive mathematically the first equation if motion

Posted by Vardaan Gupta 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Akanksha Kumari? 7 years, 1 month ago

Let a be acceleration, u be initial velocity v be final velocity and t be the time. Now, a = v - u / t at = v - u at + u = v Thus (v = u + at)- 1st equation of motion.

1Thank You

ANSWER

What do you mean by intellectual property rights?

Posted by Monu Kumar 7 years, 1 month ago

CBSE > Class 09 > Science

2 answers

Manani Chaudhary 7 years, 1 month ago

These sorry

0Thank You

Manani Chaudhary 7 years, 1 month ago

There rights are legal property rights over the creation of mind both artistic and commercial

0Thank You

ANSWER

What is squamus epithelium

Posted by Mohit Kumar 7 years, 1 month ago

CBSE > Class 09 > Science

2 answers

Yogita Ingle 7 years, 1 month ago

Squamous Epithelium – These are thin, flat cells that are closely packed. The squamous epithelial cells line the cavities of the mouth, oesophagus, alveoli, and blood vessels. This tissue gives protection against mechanical injury and also blocks the entry of germs. If the squamous epithelium is arranged in many layers, it is a compound squamous tissue called the stratified squamous epithelium. We find these kinds of tissues in the skin and also the lining of the oesophagus.

1Thank You

Mona Singh 7 years, 1 month ago

It is the type of skin tissue which is present ob ur skin

0Thank You

ANSWER

Define biogeochemical cycles

Posted by Divya Rao 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 1 month ago

The cycling of chemicals between the biological and the geological world is called biogeochemical cycle.
The biotic and abiotic components of the biosphere constantly interact through biogeochemical cycles. During these interactions, there is a transfer of nutrients between living organisms and the non-living environment.The four important biogeochemical cycles are water cycle, nitrogen cycle, carbon cycle and oxygen cycle.

1Thank You

ANSWER

Difference between speed and v

Posted by Suman Chapte 7 years, 1 month ago

CBSE > Class 09 > Science

2 answers

Shruti Cvhgj 7 years, 1 month ago

Speed =distance/time taken Velocity=displacement/timetaken Speed can not be zero Velocity can be zero Speed is scalar quantity Velocity is vector quantity

0Thank You

Yogita Ingle 7 years, 1 month ago

Velocity	Speed
Velocity can be defined as the rate at which an object changes position in a certain direction.	The rate at which an object covers a certain distance is known as speed.
Vector quantity	Scalar quantity
Velocity can be zero, negative, or positive.<	Speed can never be negative or zero.
The velocity of the object changes with the change in direction, therefore the object must follow one direction.	The average speed will continue to count even if the object change direction.
Velocity can decrease with time. For a moving object, it can be 0.	Speed never decreases with time. For a moving object, it is never 0.
An object may possess different velocities but the same speed.	Speed may or may not be equal to velocity.

1Thank You

ANSWER

Define energy?

Posted by Aditya Kumar Yadav 7 years, 1 month ago

CBSE > Class 09 > Science

2 answers

Shruti Cvhgj 7 years, 1 month ago

The ability to do work is known as energy .the si unit of energy is joule .it has two type kinetic ,and potential energy.

0Thank You

Yogita Ingle 7 years, 1 month ago

We can define energy as the strength to do any kind of physical activity. Thus, they say, ” Energy is the ability to do work “. The SI unit of energy is the same as that of work, i.e. Joules (J) which is nothing but a term for newton-meter.

0Thank You

ANSWER

Why combustion?

Posted by Pankaj Sahani 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 1 month ago

Air or oxygen which helps in burning is called supporter of combustion and the chemical reaction which takes place with the release of heat and light energy is called combustion.
A chemical process in which a substance reacts with oxygen to give off heat is called combustion.

1Thank You

ANSWER

Calculate the mass of 0.5 moles of oxygen

Posted by Ronit Rana 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Harsh Dagar 7 years, 1 month ago

Molecular mass of oxygen=16 Acc. to rule n=m/M where n=no. of moles m=given mass and M=molecular mass. So, n=0.5/16 n=5/16*10 n=1/16*2 n=1/32

1Thank You

ANSWER

What is the first orgen in embero

Posted by Dinesh Dileep 5 years, 11 months ago

CBSE > Class 09 > Science

0 answers

ANSWER

What are lichens?how they show symbiotic association?

Posted by Navjot Singh 7 years, 1 month ago

CBSE > Class 09 > Science

1 answers

Poorvi Jain 7 years, 1 month ago

A lichen is an organism that results from a mutualistic relationship between a fungus and a photosynthetic organism. The other organism is usually a cyanobacterium or green alga. The fungus grows around the bacterial or algal cells. The fungus benefits from the constant supply of food produced by the photosynthesizer

1Thank You

ANSWER

A student noted down the following observation in his notebook 1 w of the stone in air -272gwt 2. W of the stone in water - 192 gwt

Posted by Harsh Dubey 7 years, 1 month ago

CBSE > Class 09 > Science

0 answers

ANSWER

Derive the equation for work

Posted by Ashirbad Kanta Mohapatra 7 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Poorvi Jain 7 years, 1 month ago

Let the initial velocity = u, Final velocity = v, Uniform acceleration = a, and Displacement = S, then v2 - u2 = 2aS This gives S = v 2 - u 2 2a , but F = ma. Thus using above equations, we can write the workdone by the force, F as W = ma × v 2 - u 2 2a Or W = 1 2 m( v 2 - u 2 ) = 1 2 m v 2 -1 2 mu 2 = Change in kinetic energy Change in kinetic energy = W = 1 2 m( v 2 - u 2 ) = 1 2 m v 2 -1 2 mu 2 It is clear that the work done is equal to the change in the kinetic energy of an object.

0Thank You

ANSWER

What is tuberculosis

Posted by Sanjeev Jetha 7 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Gaurav Seth 7 years, 2 months ago

Tuberculosis (TB) is generally defined as an dangerous bacterial infectious disease caused by Mycobacterium tuberculosis, which most often affects the lungs and later it might spread to different parts of the body.

Types of Tuberculosis (TB)

There are two different types of Tuberculosis and are mainly categorized based on the risk factors:

Pulmonary Tuberculosis.
Extrapulmonary Tuberculosis.

0Thank You

ANSWER

Write 5 difference between physical and chemical change?

Posted by Shivam Kumar 7 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Gaurav Seth 7 years, 1 month ago

<th>BASIS FOR COMPARISON</th> <th>PHYSICAL CHANGE</th> <th>CHEMICAL CHANGE</th>

Meaning	Physical change refers to a change in which the molecules are rearranged but their internal composition remains same.	Chemical Change is a process in which the substance transforms into a new substance, having different chemical composition.
Example	Tearing of paper, melting/freezing of water, cutting of trees, etc.	Burning of wood/trees/paper, rusting of iron, setting of curd, etc.
Nature	Reversible	Irreversible
Original matter	Can be recovered	Cannot be recovered
Involves	Change in physical properties of the substance, i.e. shape, size, color etc.	Change in chemical properties and composition of the substance.
Product Formation	No new product is formed.	New product is formed.
Energy	Absorption and evolution of energy do not take place.	Absorption and evolution of energy take place, during reaction.

2Thank You

ANSWER

The figure shows a wave form of frequency 50 Hz For this wavemotion find amplitude. 2 wavelength.3 velocity

Posted by Sarah Janorkar 7 years, 2 months ago

CBSE > Class 09 > Science

0 answers

ANSWER

Which was the first satellite ???( Launched by Russia)

Posted by Mack Malik 7 years, 2 months ago

CBSE > Class 09 > Science

3 answers

Mack Malik 7 years, 2 months ago

Thanks both of you for your help

0Thank You

Divy Patidar 7 years, 2 months ago

Sputnik 2

2Thank You

Yogita Ingle 7 years, 2 months ago

Sputnik 1 was the first satellite in space. The Soviet Union launched it in 1957. NASA has launched dozens of satellites into space, starting with the Explorer 1 satellite in 1958.

2Thank You

ANSWER

A student writes scinxe paper in 3 hour .hiw much work is done by student

Posted by Mohd Ali 7 years, 2 months ago

CBSE > Class 09 > Science

2 answers

Class 12 7 years, 1 month ago

Yaar physics ke piche din raat mar jate hai wohi kehti hi k tumne koi kaam ni kiya☹

1Thank You

Sanika Deshmukh 7 years, 2 months ago

According to physics, work done by the student is zero?

1Thank You

ANSWER

Derive the law of universal gravitation.

Posted by Rahul Nuwal 7 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 2 months ago

Universal law of gravitation: The universal law of gravitation states that every object in the universe attracts every other object with a force called the gravitational force. The force acting between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.

0Thank You

ANSWER

What is eratic motion?

Posted by Amit Yadav 7 years, 2 months ago

CBSE > Class 09 > Science