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 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
This is because that a constant component of weight force is acting opposite to the direction of motion of our vehicle. This cause our vehicle to apply more power and that is why it consumes more fuel.
When you push there is one component of force that adds to the weight of the body and hence there is more friction. When you pull the vertical component of force is against the weight of body and hence there is less overall friction. So it is easy to pull than push an object.
Because of Newton's second law of motion.
Before hitting the cricketerâ€™s hand, the ball was travelling with a speed "v" and after hitting his hand, since the speed reduces to zero in very less time, so the rate of change of momentum that is the force is very large.
That is why the cricketer used to lowers his hand. By doing this,he reduces the speed of the ball slowly to zero instead of...