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प्रश्न
Answer the following in a word or two or in a sentence.
Why is difficult for a pen to leave a mark on a highly smooth plastic sheet?
उत्तर
Because the smooth surface has very less friction.
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संबंधित प्रश्न
Explain why sportsmen use shoes with spikes.
Define rolling friction
A body needs a force F1 just to start moving on a surface, a force F2 to continue its motion and a force F3 to roll on the surface. What is
- the static friction
- sliding friction and
- rolling friction? State whether F2 is equal, less than or greater than (1) F1 and (2) F3.
Fill in the blank.
More the roughness of a surface, greater is the ........................
Fill in the blank.
Friction depends upon the ............... of an object.
How do you feel when you touch a nail immediately after it is hammered into a wooden plank? Why?
In figure, a boy is shown pushing the box from right to left. The force of friction will act on the box
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. Give reason.
Friction depends on the ______ of two surfaces in contact.
Assertion: We can live very happily if friction is not present in nature.
Reason: The airplane shape is streamlined to reduce the effort of frictional force.
