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प्रश्न
Answer in short.
State advantages of friction.
उत्तर
Advantages of friction:
- We can walk due to friction between the ground and feet.
- We can hold objects in hand due to static friction.
- Brakes of vehicles work due to friction; hence we can reduce speed or stop vehicles.
- Climbing on a tree is possible due to friction.
APPEARS IN
संबंधित प्रश्न
Answer in one sentence.
Define friction.
Answer in one sentence.
Why force of static friction is known as ‘self-adjusting force’?
Answer in one sentence.
Name two factors on which the coefficient of friction depends.
State any four methods to reduce friction.
Answer in short.
What is rolling friction? How does it arise?
Answer in short.
Explain how lubricants help in reducing friction.
Answer in short.
State the laws of static friction.
Answer in short.
State the laws of kinetic friction.
State disadvantages of friction.
Long answer type question.
Define coefficient of static friction and coefficient of kinetic friction. Give the necessary formula for each.
Calculate the coefficient of static friction for an object of mass 50 kg placed on horizontal table pulled by attaching a spring balance. The force is increased gradually it is observed that the object just moves when spring balance shows 50 N.
Answer the following.
A block of mass 37 kg rests on a rough horizontal plane having coefficient of static friction 0.3. Find out the least force required to just move the block horizontally.
A body of mass 37 kg rests on a rough horizontal surface. The minimum horizontal force required to just start the motion is 68.5 N. In order to keep the body moving with constant velocity, a force of 43 N is needed. What is the value of coefficient of static friction?
