Question 2 :
State true or false: When the cutting edge of a knife is put against a fast rotating stone to sharpen it, sparks are seen to fly.
Question 3 :
Iqbal has to push a lighter box and Seema has to push a similar heavier box on the same floor . Who will have to apply a larger force?
Question 4 :
Friction opposes the ___________ between the surfaces in contact with each other.
Question 5 :
You spill a bucket of soapy water on a marble floor accicdentally . Would it make it easier or more difficult for you to walk on the floor?
Question 6 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d071f59b460d7261f2f0.PNG' />
In the above image, While playing tug of war Preeti felt that the rope was slipping through her hands. Which of the following is a way out for her to prevent this?
Question 7 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d070f59b460d7261f2ef.PNG' />
In the above image, a boy is shown pushing the box from right to left.The force of friction will act on the box
Question 9 :
Four children were asked to arrange forces due to rolling, static and sliding frictions in decreasing order. Their arrangements are given below. Choose the correct arrangement.
Question 10 :
Can you hold a glass or write on the board with a chalk without any friction?
Question 11 :
The frictional force also depends on the _____ of the object and the _______ of the fluid respectively.
Question 12 :
Alida runs her toy car on a dry marble floor, wet marble floor, newspaper and towel spread on the floor. The force of friction acting on the car on different surfaces in increasing order will be
Question 14 :
Will force of friction come into play when a rain drop rolls down a glass window pane?
Question 15 :
If you place a book over 3 cylindrical pencils and push it, is it easier to move the book this way?
Question 16 :
To reduce friction, the shape of an aeroplane is made similar to which organism?
Question 17 :
You spill a bucket of soapy water on a marble floor accidentally. Would it make it easier or more difficult for you to walk on the floor?
Question 18 :
You spill a bucket of soapy water on a marble floor accicdentally . Would it be dificult for you to walk on the floor ? Choose the correct reason of your answer.
Question 20 :
Why the surface of mortar and pestle (silbatta) used for grinding is etched again after prolonged use?
Question 24 :
Friction opposes relative motion between the surfaces of the book and the table. True or false?
Question 27 :
Four children wore asked to arrange forces due to rolling, static and sliding frictions in a decreasing order. Their arrangements are given below. Choose the correct arrangement.
Question 29 :
How do objects overcome the force of friction exerted by fluids on them?
Question 30 :
Which force comes into play when you push a book on a table?
Question 32 :
What happens to the strength of frictional force when logs are lifted by placing logs under it?
Question 33 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d0daf59b460d7261f376.PNG' />
From the above figure, if you tie a string around a brick and pull it by spring balance and then wrap a polythene on it and repeat the activity, will the spring balance measurement show any difference?
Question 35 :
When the cutting edge of a knife is put against a fast rotating stone to sharpen it, sparks are seen to fly due to which of the following reason(s)?
Question 37 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d0d9f59b460d7261f375.PNG' />
From the above figure, if you tie a string around a brick and pull it by spring balance, what will the spring balance measure?
Question 38 :
If an object started moving, it would never stop if there were no friction.
Question 39 :
State true or false: There is rolling friction between the wheels of a moving train and iron rails.
Question 43 :
Friction can never be entirely eleminated because no surface is perfectly smooth. Some irregularities are always there. True or false?
Question 44 :
Imagine that an object is falling through a long straight glass tube held vertical; air has been removed completely from the tube. The object does not touch the walls of the tube. Will the object experience any force of friction?
Question 45 :
In a large commercial complex there are four ways to reach the main road. One of the path has loose soil, the second is laid with polished marble, the third is laid with bricks and the fourth has gravel surface. It is raining heavily and Paheli wishes to reach the main road. The path on which she is least likely to slip is
Question 46 :
Spring balance consists of ________ which gets stretched when a force is applied to it.
Question 48 :
We have two identical metal sheets. One of them is rubbed with sand paper and the other with ordinary paper. The one rubbed with sand paper shines more than the other due to which of the following reasons?
