English Medium इयत्ता ९ - CBSE Question Bank Solutions for Science

Fill in the following blank with suitable word :

Displacement is a…………………… quantity whereas distance is a………………………….

The displacement of a moving object in a given interval of time is zero. Would the distance travelled by the object also be zero ? Give reason for your answer.

What is the difference between distance travelled  by a body and its displacement ? Explain with the
help of a diagram.

An ant travels a distance of 8 cm from P to Q and then moves a distance of 6 cm at right angles to PQ. Find its resultant displacement.

A body is moving along a circular path of radius R. What will be the distance travelled and displacement of the body when it completes half a revolution ?

If on a round trip you travel 6 km and then arrive back home :

What distance have you travelled ?

If on a round trip you travel 6 km and then arrive back home :

What is your final displacement ?

A body travels a distance of 3 km towards East, then 4 km towards North and finally 9 km towards East.

What is the total distance travelled ?

A body travels a distance of 3 km towards East, then 4 km towards North and finally 9 km towards East.

What is the resultant displacement ?

A boy walks from his classroom to the bookshop along a straight corridor towards North. He covers a distance of 20 m in 25 seconds to reach the bookshop. After buying a book, he travels the same distance in the same time to reach back in the classroom. Find (a) average speed, and (b) average velocity, of the boy.

What is the usual name of the forces which cannot produce motion in a body but only change its shape ?

Name the unbalanced force which slows down a moving bicycle when we stop pedalling it.

State whether the following statement is true or false :
Unbalanced forces acting on a body change its shape.

State whether force is a scalar or a vector quantity?

Fill in the following blank with suitable word:

When a running car stops suddenly, the passengers are jerked …………………..

Fill in the following blank with suitable word :

When a stationary car starts suddenly, the passengers are jerked …………………..

Fill in the following blanks with suitable word :

If there were no unbalanced force of……………….. and no…………………. resistance, a moving bicycle would go on moving for ever.

Which of the two, balanced forces or unbalanced forces, can change the shape of an object ? Give an example to illustrate your answer.

Give reason for the following :
When a hanging carpet is beaten with a stick, the dust particles start coming out of it.

Explain why, it is dangerous to jump out of a moving bus.