Question 1 :
A marble is allowed to roll down an inclined plane from a fixed height. At the foot of the inclined plane, it moves on a horizontal surface (a) covered with silk cloth (b) covered with a layer of sand and (c) covered with a glass sheet. On which surface will the marble move the shortest distance.

Question 2 :
If an air cushion can be introduced between the wheel and the rail, what effect will it have on the friction?

Question 4 :
What is easier to move the box from rest, or to move it when it is already in motion?

Question 5 :
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 6 :
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 8 :
A toy car released with the same initial speed will travel farthest on

Question 10 :
<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 11 :
The handle of a cricket bat or a badminton racquet is usually rough. Which of the following is the reason for it?

Question 13 :
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 farthest distance?

Question 14 :
Can you hold a glass or write on the board with a chalk without any friction?

Question 15 :
Friction can never be entirely eleminated because no surface is perfectly smooth. Some irregularities are always there. True or false?

Question 16 :
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 20 :
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