In this chapter, you have completed:
More than 35 doubts, important facts, points to remember etc.
More than 90 number of Questions, Solutions, and Examples
In this chapter, firstly you read "Laws of motion” and then moved to “applications of Laws of motion”. Apart from this there are certain tips for you which will be helpful for you to develop a lot of interest in this chapter....
Friction between the sliding surfaces of two objects can be reduced by making the surfaces in contact smooth by polishing them. Sliding friction between the moving parts of vehicles can be reduced by using oil, grease or graphite.
For example - For a circular surface, the direction of the normal force exerted by circular surface is perpendicular to the tangent of that point. So, that direction will meet the center of that circular surface
The term rolling friction refers to the resistance created by an object rolling across a surface. Examples of rolling friction can help you to understand this concept. You will understand this well in Rotation chapter.
Yes, sometimes friction can act in the direction of motion. For example:- A car accelerates on the road only because the frictional force on the car due to the road drives it, i.e., the car would not accelerate if tires did not push against the road and the road pushed against tires. The force that accelerates your car is the static friction against your tires in the direction you are accelerating.
In the above figure
1) If pulled slowly string will break from point A.
2) If pulled with a sudden jerk then it will experience Tension & due to inertia of rest of mass(load) F will not be transmitted to point A,
so it will break from B point