English Medium इयत्ता ९ - CBSE Question Bank Solutions for Science

Comment upon the following:-

fluidity

Comment upon the following:-

filling a gas container

Comment upon the following:- 

shape

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kinetic energy

Comment upon the following:-

density

To make a saturated solution, 36 g of sodium chloride is dissolved in 100 g of water at 293 K. Find its concentration at this temperature.

Explain the term Saturated solution giving examples.

Why is it not possible to see an atom with naked eyes?

If bromine atom is available in the form of, say, two isotopes `""_35^79Br (49.7%)" and """_35^81Br (50.3%)`, calculate the average atomic mass of bromine atom.

The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes `""_8^16X" and """_8^18X` in the sample?

Name types of simple tissues.

What are the constituents of phloem?

When will you say a body is at non-uniform acceleration?

A bus decreases its speed from 80 km h⁻¹ to 60 km h⁻¹ in 5 s. Find the acceleration of the bus.

A train starting from a railway station and moving with uniform acceleration attains a speed 40 km h⁻¹ in 10 minutes. Find its acceleration.

A mass of 10 kg is at a point A on a table. It is moved to a point B. If the line joining A and B is horizontal, what is the work done on the object by the gravitational force? Explain your answer.

The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy? Why?

Which of the two can be zero under certain conditions : average speed of a moving body or average velocity of a moving body ?

Give one example of a situation in which a body has a certain average speed but its average velocity is zero.

Name the physical quantity whose SI unit is :
(a) m/s (b) m/s²