Answer:

a) Who will help the labourer more – Ram or Shyam?

Shyam will help the labourer more by providing two iron bars and asking the labourer to put them below the box. This is because the iron bars reduce the friction between the box and the ground, making it easier to move the heavy box.

When Ram helps the labourer by pushing the box with him, the friction between the box and the ground remains the same. Although the force applied to the box is increased, the frictional force is also increased proportionally, making it harder to move the box. Therefore, Ram's effort alone does not significantly help the labourer to move the box.

b) Factors that affect friction:

Friction is the force that opposes the relative motion or tendency of motion between two surfaces in contact. The factors that affect friction are as follows:

1. Nature of the Surfaces:
- The nature of the surfaces in contact determines the frictional force. Rough surfaces have more friction compared to smooth surfaces. For example, it is easier to slide a book on a smooth table compared to a rough carpet.

2. Normal Force:
- The normal force is the force exerted by a surface perpendicular to the contact area. Frictional force is directly proportional to the normal force. Greater the normal force, greater is the friction. For example, it is easier to push a heavy object on a horizontal surface compared to a vertical surface.

3. Roughness of the Surfaces:
- The roughness of the surfaces in contact affects friction. Rough surfaces have more microscopic bumps and irregularities, resulting in more friction. Smoother surfaces have fewer irregularities, resulting in less friction.

4. Weight or Force Applied:
- Frictional force is directly proportional to the weight or force applied. Greater the weight or force, greater is the friction. For example, it is easier to slide a lighter object compared to a heavier one.

5. Lubrication:
- Lubrication reduces friction between surfaces. It forms a thin layer between the surfaces, reducing the contact area and allowing smoother movement. For example, oil or grease is used to lubricate the moving parts of machines.

6. Temperature:
- Temperature affects friction. In some cases, an increase in temperature can reduce friction, while in other cases, it can increase friction. For example, the friction between car tires and the road increases in cold weather.

In conclusion, the nature of the surfaces, normal force, roughness of the surfaces, weight or force applied, lubrication, and temperature are the factors that affect friction. Understanding these factors helps us make informed decisions to reduce or increase friction as required.