Static Friction

Q.

List the disadvantages of friction.

Q.

Definition of static friction.

Q.

Of the various types of friction, which has the maximum value between two surfaces in contact?

1. Walking

2. Rolling

3. Sliding

4. Static

Q. Question 17
While playing tug of war, Preeti felt that the rope was slipping through her hands. Suggest a way out for her to prevent this.

Q.

A horizontal force of $10N$ is acting on the block which doesn't change its motion. Static friction acting on the block is ___newtons.

Q.

Which of the following statements is incorrect?

1. Friction opposes relative motion of objects.

2. Friction produces heat.

3. Friction is never useful

4. Friction can stop a moving object.

Q.

How is the heat produced by friction both an advantage and a disadvantage?

Q. The force which opposes an external force acting on a body while it is still at rest is called .

1. Static friction
2. Sliding friction
3. Kinetic friction

Q. A rough surface produces a/an _____ friction as/than a smooth surface.

1. lesser
2. greater
3. equal
4. opposite

Q.

What do you understand by the term Force of friction and state three effects of force of friction?

Q.

A horizontal force of $20N$ is acting on the block which is at rest. Static friction acting on the block is

1. $0N$

2. $10N$

3. $25N$

4. $20N$

Q.

Give reasons for the following.

1. A bicycle comes to rest slowly when the cyclist stops paddling.

Q.

Is there friction in the atmosphere and the solar system ?

Q. Which of the following is the correct order of various types of friction?

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

Q. Why a horse need to pull harder during the first few steps in pulling the cart?

1. Limiting friction is greater than dynamic friction.
2. Sliding friction is greater then rolling friction.
3. No frictional force acts after the cart comes in motion.
4. Air friction is greater is greater during first few stops of motion.

Q.

State any three disadvantages of friction.

Q. Distinguish between static friction, limiting friction and kinetic friction.How do they vary with the applied force? Explain by diagram.

Q. Before using the beam balance why is the beam raised gently by raising the platform?

1. To make one side of the beam balance heavy
2. To ensure that the pointer swings equally on both sides of the zero mark on scale
3. Both
4. None

Q.

A block of mass $m$ is at rest while a force is acting on it horizontally. What type of friction is opposing the movement of the block?

1. Rolling friction

2. Kinetic friction

3. Static friction

4. All of the above

Q.

A block needs $50N$ of force to move and you are applying $5N$ of force on that block in the horizontal direction. The frictional force acting on the block is ___ newtons.

Q.

what is sliding friction?

Q. ntWhat is the formula for rolling friction ?n

Q. Frictional force is important for motor racing. This is because frictional force.

1. Can help a car to slow down
2. Can help a car to move faster
3. Can help a car move around the corners without skidding
4. None of these

Q. Frictional force exists in which of the following cases ?

1. Exists only for moving bodies.
2. Exists only for bodies which are at rest.
3. Exists for both moving and non-moving bodies.
4. None of these

Q. A block of mass m is attached with a massless spring of force constant k. The block is placed over a rough inclined surface for which the coefficient of friction is 0.5. M is released from rest when the spring was unstretched. The minimum value of M required to move the block m up the plane is (neglect mass of string and pulley and friction in pulley)

1. m/2
2. m/3
3. m/4
4. m

Q. Types of friction are:-

Q.

The force which opposes an external force acting on a body while it is still at rest is called:

1. Sliding friction

2. Magnetic force

3. None of these

4. Static friction

Q. Assertion :Statement 1 : When static friction acts, there is no loss of mechanical energy. Reason: Statement 2 : When kinetic friction acts between two bodies, there is loss of mechanical energy.

1. Both Statements 1 and 2 are true and Statement 2 is the correct explanation of Statement 1.
2. Both Statements 1 and 2 are true, but Statement 2 is not the correct explanation of Statement 1.
3. Statement 1 is true but Statement 2 is false.
4. Statement 1 is false but Statement 2 is true.