Friction General Understanding
Trending Questions
Q. Which of the following statements is correct regarding friction?
- It always acts opposite to the applied force.
- It always opposes motion.
- It always acts opposite to relative velocity.
- All of these
Q. Which of the following statements is true about kinetic friction?
- It is a self-adjusting force.
- It depends on the external force applied on the body.
- It depends on the area of contact.
- It depends on the nature of surfaces of contact.
Q. A cubical block rests on a plane of μ=√3. The angle through which the plane should be inclined to the horizontal so that the block just slides down will be
- 30∘
- 45∘
- 60∘
- 75∘
Q. Find the direction of friction on A and B at the surfaces of contact between them (for the figure shown).
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/794087/original_download_%2818%29.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/794087/original_download_%2818%29.png)
- Left, Right
- Right, Left
- Left, Left
- Right, Right
Q. If μr, μk and μs represent the coefficients of rolling friction, kinetic friction and static friction, then
- μr>μk>μs
- μr<μk>μs
- μr<μk<μs
- μr>μk<μs
Q. Which of the following statements is true about kinetic friction?
- It is a self-adjusting force.
- It depends on the external force applied on the body.
- It depends on the area of contact.
- It depends on the nature of surfaces of contact.
Q. A scooter starting from rest moves at constant acceleration for time Δ t1, then with a constant velocity for Δt2 and finally with a constant deceleration for time Δt3 to come to rest. A man of the weight of 200 N sitting behind the driver manages to be at rest with respect to the scooter without touching any other part of the scooter. The contact force exerted by the seat on the man is
- 200 N throughout the journey.
- Less than 200 N throughout the journey.
- More than 200 N throughout the journey
- More than 200 N for time Δt1 and Δt3 and 200 N for Δt2
Q. A block starts slipping down an inclined plane and moves half a meter in half-second. How long will it take to cover the next half meter (in sec)?
Q. Find the direction of friction on A and B at the surfaces of contact between them (for the figure shown).
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/794087/original_download_%2818%29.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/794087/original_download_%2818%29.png)
- Left, Right
- Right, Left
- Left, Left
- Right, Right
Q. The retarding acceleration of 4 m/s2 due to frictional force stops a block of mass 40 kg moving on a rough horizontal surface. The coefficient of friction between the block and the surface is
- 0.3
- 0.4
- 0.55
- 0.65
Q. Two cars of unequal masses use similar tyres. If they are moving at the same initial speed, the minimum stopping distance
- is smaller for the heavier car
- is smaller for the lighter car
- is same for both cars
- depends on the volume of the car
Q. In the figure shown, find the direction of friction on A and B respectively on the surface, which is in contact with the surface of block A.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/776206/original_5.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/776206/original_5.png)
- Forward, Backward
- Backward, Backward
- Backward, Forward
- Forward, Forward
Q. In the figure, block m1 is loaded on block m2. If there is no relative sliding between the blocks and the inclined plane is smooth, the frictional force acting between the blocks is:
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/845559/original_Asset_8.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/845559/original_Asset_8.png)
- μm2sinθ
- μm1cosθ
- μm1sinθ
- Zero
Q. A block of mass 5 kg is resting on a rough horizontal surface. Now a force of 24 N is imparted to it with a negligible impulse as shown in the figure. If the coefficient of kinetic friction is 0.4 and g=10 m/s2, then the acceleration of the block will be
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/794112/original_download_%2834%29.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/794112/original_download_%2834%29.png)
- 0.26 m/s2
- 0.39 m/s2
- 0.69 m/s2
- 0.8 m/s2
Q. A cubical wooden box of side L is placed on a horizontal rough surface and the coefficient of static friction between them is μ. Another cubical box of the same wood but of side 2L is placed on the same surface. Then the coefficient of static friction is
- 8μ
- 4μ
- 2μ
- μ
Q.
In the following figure, find the direction of friction on the blocks A and B and the ground respectively.
- Backwards, forwards, backwards
- Backwards, backwards, forwards
- Forwards, forwards, backwards
- Forwards, backwards, forwards
Q. In the figure shown, find the direction of friction on blocks B and C at the surface which is common to the blocks B and C respectively.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/779223/original_original_5_%282%29.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/779223/original_original_5_%282%29.png)
- Forward, Backward
- Backward, Backward
- Backward, Forward
- Forward, Forward
Q. In the figure shown, find the direction of friction on block A.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/958373/original_original_02_S1.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/958373/original_original_02_S1.png)
- Forward
- Backward
- Upward
- Downward
Q. A wooden block which is being acted upon by forces F1=10 N, F2=2 N is at rest on a rough horizontal plane as shown in figure. If force F1 is removed, the resultant force acting on the block will be
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/970153/original_26.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/970153/original_26.png)
- 2 N towards left
- 2 N towards right
- Zero
- Cannot be determined.
Q. Find the direction of friction on A and B respectively at the common surface between blocks A and B for the figure shown.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/794103/original_download_%2829%29.png)
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/794103/original_download_%2829%29.png)
- Forward, Backward
- Backward, Backward
- Backward, Forward
- Forward, Forward