Question

1. Explain Why, it is easier to drag a mat on floor when nobody is sitting on
it but much more difficult to drag the same mat when a person is sitting
on it.
2. What are the factors affecting friction? Explain with examples.
3. What is the cause of friction? Explain with the help of labeled diagram.
4. Which type of surfaces produce {a} least friction, and {b} too much
friction?
5. What is the direction of force of friction acting on a moving object?
6. A car is moving towards North. What will be the direction of force of
friction acting on this car due to surface of road?

Answer 1

Answer:

1. Friction. ... Friction is caused by the inter locking of the irregularities in the two surfaces. When two surfaces are pressed harder together, the force of friction increases. Therefore, it is easy to drag a mat when no body is sitting on it rather than when a person is sitting on it.
2. Various factors which affect friction are: Smoothness of surface:-more the surface is smooth, less is the friction. Normal force: This is also the most important factor responsible for friction. Normal force itself depends on weight of the body
3. The cause of friction is surface roughness and adhesion.
4. smooth surfaces produce least friction why rough surfaces produce too much friction. Smooth and polished surface provides least friction.
5. Frictional force offers the resistance to the applied force opposing its motion. Thus, it always acts in the direction opposite to that of the object in motion. If force is applied to the left, then friction acts in the right
6. south direction.Always the force due the friction on a car moving in a north direction is in south direction,because the frictional force is always in a opposite direction to which the object moves.

Answer 2

The friction between the mat and the ground increases in the second case which reduces the net force applied on it. This is because frictional force is directly proportional to the 'weight' of the body that moves with respect to a surface. So in the second case, the weight of the body (mat+Person) is higher and would have more friction that would oppose the motion.