English Medium इयत्ता ९ - CBSE Question Bank Solutions for Science

Give one example where a force stops a moving body .

When a toothpaste tube is squeezed, its shape changes. The force responsible for this is an example of :

When we talk of a force acting on a body, it usually means :

If we release a magnet held in our hand, it falls to the ground. The force which makes the magnet fall down is an example of :

When a rubber balloon held between the hands is pressed, its shape changes. This happens because :

Which of the following effect cannot be produced by an unbalanced force acting on a body?

A boy of mass 50 kg standing on ground exerts a force of 500 N on the ground. The force exerted by the ground on the boy will be :

A fielder pulls his hands backwards after catching the cricket ball. This enables the fielder to :

Which of the following is the speed of sound in copper and which in aluminium?
(a) 5100 m/s
(b) 1500 m/s
(c) 3750 m/s

If you want to hear a train approaching from far away, why is it more convenient to put the ear to the track?

What is the speed of sound :
(a) in air?
(b) in water?
(c) in iron?

What name is given to those aircrafts which fly at speeds greater than the speed of sound?

Which of the following travels slowest in air and which one fastest? Supersonic aircraft, Light, Sound

Which subatomic particle is not present in an ordinary hydrogen atom?

A cricket ball is seen to hit the bat first and the sound of hitting is heard a little later. Why?