Question

I NEED HELP PLEASE!

1. 3 statements about limiting frictional force between two surfaces are given below.


A - Nature of surfaces in contact affects to limiting frictional force.

B - Normal reaction between them affects to limiting frictional force.

C - Area of surfaces in contact affects to limiting frictional force.


Correct statement / statements from above A, B, C is/ are,

(1) A

(2) B

(3) A and C

(4) A, B and C

Answer 1

The correct statement is (3) A and C.

The limiting frictional force between two surfaces is dependent on the nature of the surfaces in contact and the area of the surfaces in contact. The normal reaction between them is not a factor affecting the limiting frictional force.

Answer 2

Let's analyse the options:

• Option 1: Statement A is correct. The nature of surfaces in contact determines the friction between them. Rough and irregular surfaces have higher friction than smooth surfaces.
• Option 2: Statement B is incorrect. The normal reaction between the surfaces does not affect the limiting frictional force. Only the maximum static friction depends on the normal reaction.
• Option 3: Statements A and C are correct. Both nature of surfaces and area of contact determine the friction between them.
• Option 4: All statements A, B and C are incorrect. Nature of surfaces, normal reaction and area of contact affect the limiting frictional force between two surfaces.

The limiting frictional force depends only on:

1. A. The nature of surfaces in contact: Rough and irregular surfaces have higher friction than smooth surfaces.
2. C. The area of surfaces in contact: Larger the contact area, higher is the friction between the surfaces.

(3) A and C is the right option