Advertisements
Advertisements
प्रश्न
Suppose your writing desk is tilted a little. A book kept on it starts sliding down. Show the direction of frictional force acting on it.
Advertisements
उत्तर
When a book slides on the writing desk, a frictional force acts between the book and the surface of the desk. The direction of the frictional force on the book is opposite to the direction of its motion and acts upward, as shown in the following figure.
संबंधित प्रश्न
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 and why?
List three ways of reducing friction.
Give three examples to illustrate that friction is a necessary evil.
Arrange the following in descending order:
- static friction
- sliding friction and
- rolling friction?
Answer the following in a word or two or in a sentence.
Which type of force acts on a string pulled from both ends?
Tick the most appropriate answer.
Force of friction comes into play when a/an
Tick the most appropriate answer
Friction always
Tick the most appropriate answer.
Friction is offered by
Tick the most appropriate answer.
Friction produces
Tick the most appropriate answer.
If you pour some oil onto a floor, the friction would
State if the following statement is true or false. Correct the statement if it is false.
Friction has no relation with our walking or running.
Answer the following in detail.
Define friction and explain how it is useful to us.
How do you feel when you touch a nail immediately after it is hammered into a wooden plank? Why?
Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play
In the following figure, a boy is shown pushing the box from right to left. The force of friction will act on the box
Analogy
Objects placed at rest on earth: ______:: Bodies slide over the surface on other body: ______.
Assertion: Friction always opposes the motion.
Reason: Whenever one surface moves or tries to move over another surface, the force of friction starts acting on the surfaces.
Complete the analogy.
Knot in a thread : ______ friction :: Ball bearing : ______ friction.
