Question

Q.1 Define rolling friction and give an example where rolling friction comes into play.
Q.2What is the basic principle for increasing friction?
Q.3 Why do wrestlers rub a special substance on their hands before getting into the ring?
Q.4 What is 'stremlining'?​

Answer 1

Answer:

1. When we roll an object on a surface, the friction produced between the object and the surface is called rolling friction. Example: when we pull our large suitcases on wheels, rolling friction comes into play.
2. The basic principle for increasing friction is by increasing the roughness of the surfaces in contact.
3. Wrestlers rub their hands with soil so that they get a better grip on the opponent. wrestlers use to rub some special substances and soil in their hand before entering into the ring to get grip on their opponent which make the fight much easier.
4. Streamlining, in aerodynamics, the contouring of an object, such as an aircraft body, to reduce its drag, or resistance to motion through a stream of air. ... Streamlining, then, is the contouring of an aircraft or other body in such a way that its turbulent wake is reduced to a minimum.

Answer 2

Answer:

1.When we roll an object on a surface, the friction produced between the object and the surface is called rolling friction

2. The basic principle for increasing friction is by increasing the roughness of the surfaces in contact.

3. Wrestlers rub their hands with soil so that they get a better grip on the opponent. wrestlers use to rub some special substances and soil in their hand before entering into the ring to get grip on their opponent which make the fight much easier

hope it helps u !!