Question 3 :
The frictional force also depends on the _____ of the object and the _______ of the fluid respectively.
Question 4 :
It is obvious that the force of friction will ______ if the two surfaces are pressed harder.
Question 5 : <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 6 :
Cartilage is present in the joints of our body, which helps in their smooth movement. With advancing age, this cartilage wears off. How would this affect the movement of joints?
Question 7 :
A toy car released with the same initial speed will travel farthest on
Question 10 :
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 11 :
If you roll a pencil from an inclined plane, then cover the surface by cloth and roll the pencil again. In which case does it travel the least distance?
Question 12 :
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 14 :
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 15 : <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 18 :
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 19 :
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 20 :
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 21 :
Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play
Question 22 :
Friction opposes relative motion between the surfaces of the book and the table. True or false?
Question 24 : <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 26 :
If an object started moving, it would never stop if there were no friction.
Question 28 :
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?
Question 30 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d072f59b460d7261f2f1.PNG' />
In the above image, Two blocks of iron of different masses are kept on a cemented floor.Which one of them would require a larger force to move it from the rest position?
Question 31 :
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 32 :
Why the surface of mortar and pestle (silbatta) used for grinding is etched again after prolonged use?
Question 34 :
Two boys are riding their bicycles on the same concrete road. One has new tyres on his bicycle while the other has tyres that are old and used. Which of them is more likely to skid while moving through a patch of the road which has lubricating oil spilled over it?
Question 35 :
If an air cushion can be introduced between the wheel and the rail, what effect will it have on the friction?
Question 37 :
How do objects overcome the force of friction exerted by fluids on them?
Question 38 :
Friction can never be entirely eleminated because no surface is perfectly smooth. Some irregularities are always there. True or false?
Question 39 :
Does the distance covered depend on the nature of the inclined surface on which the object rolls over?
Question 40 :
To sharpen the blade of a knife by rubbing it against a surface, which of the following will be most suitable?
