English Medium Class 9 - CBSE Question Bank Solutions for Science

Why does a sharp knife cut objects more effectively than a blunt knife ?

Explain why, a wide steel belt is provided over the wheels of an army tank.

Explain why, the tip of a sewing needle is sharp.

Name the force which wears away two surfaces as they move over one another.

Name the force which pulled the apple off Isaac Newton’s tree.

Name the force which stops you falling through the floor.

A pressure of 10 Pa acts on an area of 3.0 m². What is the force acting on the area ? What force will be exerted by the application of same pressure if the area is made one-third ?

"A substance has a definite shape as well as a definite volume." Which physical state is represented by this statement?

Give one example of the diffusion of a solid in another solid.

Explain why, the diffusion of a solid in another solid is a very slow process.

State two characteristic properties of a solid.

How do solids, liquids and gases differ in shape and volume?

Arrange the following substances in increasing order of force of attraction between their particles (keeping the substance having the minimum force of attraction first) : Water, Sugar, Oxygen

Give two reasons to justify that An iron almirah is a  solid.

Compare the properties of solids, liquids and gases in tabular form.

Give two reasons for saying that wood is a solid.

‘‘The properties of the product are different from those of the constituents''. State whether this statement best describes an element, a compound or a mixture.

What is the major difference between a solution and an ordinary mixture ?

Fill in the following blanks with suitable words :

Brine is a ..............whereas alcohol is a...............