Sliding Friction

Q. Which among the following is the correct order of frictional force acting between the same pair of bodies?

1. Rolling friction > Sliding friction > Static friction
2. Static friction > Sliding friction > Rolling friction
3. Sliding friction > Static friction > Rolling friction
4. Sliding friction > Rolling friction > Static friction

Q. What will happen to a moving object if there is no friction?

1. The object will deflect from its original path.
2. The object will keep on moving.
3. The object will stop immediately.
4. The object will stop after travelling some distance.

Q. When an object moves through a liquid, it experiences __________.

1. rolling friction
2. fluid friction
3. static friction
4. sliding friction

Q.

When you push something heavy , the restance you fell decrease as the body stars moving . Explain what happens .

Q.

What is difference between sliding friction and static friction?

Q.

On which of the following surfaces would a toy car travel the farthest distance when a kid pushes it?

1. Wet marble floor

2. Dry marble floor

3. Newspaper

4. Towel

Q. A small coin is placed on a flat horizontal turn table. The turn table is observed to make three revolutions in 3.14 sec. What is the coefficient of static friction between the coin and turn table if the coin is observed to slide off the turn table when it is greater than 10 cm from the centre of turn tab

Q.

What do you understand by the term streamlining?

Q.

What is kinetic friction

Q.

What do you understand by the term “streamlining”? Give examples where the bodies are streamlined and give a reason?

Q. Identify the type of friction acting in the following figure:

1. Static friction
2. Sliding friction
3. Fluid friction
4. Rolling friction

Q. If you apply 12 N force to a block on a horizontal surface then it starts its movement. Now if you apply 15 N force to it then what will be the frictional force on it?

1. Equal to 12 N
2. Less than 12 N
3. Greater than 12 N
4. Equal to 0 N

Q. Answer the following question:

A. Why is sliding friction less than static friction for the same surface?

B. A book of mass 1 kg is at rest on the table. Maximum value of static friction is 5N and sliding friction is 4N.
Now, Answer:

i. If we apply a force of 4.5N will the body move from rest?
ii. If we apply a force of 6N will the body move from rest?
[5 MARKS]

Q.

Rolling friction is always greater than sliding friction.

1. True
2. False

Q. EXPLAIN WHY SLIDING FRICTION IS LESS THAN STATIC FRICTION.

Q.

Why sliding friction is less than static friction?

Q. Find out how friction heat up food in microwave ovens?

Q. A horizontal force of 20 N is applied on a box placed on a flat surface and it just starts to move. What will be the value of sliding friction?​

Q.

What happens to static friction when a wooden block is moved with increasing speed on a horizontal surface?

Q. On applying brakes, helps the speed of vehicles.

1. decrease
2. maintain
3. friction
4. gravitation

Q.

Explain static friction with the formula.

Q. A block is placed on an inclined plane. If the block remains stationary, which of the following statements is correct?

1. No friction acts on the block.
2. Static friction acts on the block and its direction is down the inclined plane.
3. Sliding friction acts on the block and its direction is up the inclined plane.
4. Static friction acts on the block and its direction is up the inclined plane.

Q.

State whether the following statement is true or false:

The force of friction is never useful to us.

1. True
2. False

Q. Select the examples in which sliding friction is acting on the body.

1. 
2. 
   
3. 
4. Parked Car
   

Q.

Device to change sliding friction into rolling friction _________

Q. Select the correct statements about the friction between the two bodies.

1. Rolling friction is greater than sliding friction.
2. Maximum static friction is greater than rolling friction.
3. Sliding friction is greater than rolling friction.
4. All types of friction are equal.

Q.

What is the advantage of using ball bearings in machines?

1. Sliding friction replaces rolling friction.

2. Static friction replaces rolling friction.

3. Rolling friction replaces sliding friction.

4. Rolling friction replaces static friction.

Q.

Why is sliding friction less than static friction? [3 MARKS]

Q. Question 1
Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play

(a) only if the objects are solid.
(b) only if one of the two objects is liquid.
(c) only if one of the two objects is gaseous.
(d) irrespective of whether the objects are solid, liquid or gaseous.

Q. If contact forces (repulsion between atoms) does not exist then how friction is possible ?