85% Students don’t know Basics of Friction | Eye opener JEE PHYSICS

Friction and Newton’s laws of motion is a fundamental topic of class 11 JEE Physics but 85% students don’t know the basics of friction in JEE Physics. This video is an explanation of some basic concepts of friction by Ashish Arora sir to build a strong OTBT thinking on topic of friction.

#frictionforjee #frictionforneet #frictininPhysics #class11physics #friction #newtonslawsofmotion #physicsgalaxy #ashisharora

[aryankataria]

I am sitting in Jossa 2023 and got NIT Allahabad also but still feels soo good of seeing our old good concepts ...
FOR ONE WHO ARE IN PREPARATORY PHASE
trust me it is one of the first whose gonna shape you and your career in a whole new direction...
Good luck buddy's

[adityakrsingh-urll]

actually i thought i would go vertically outward but not tangentially...but i did not think of vector sum of both sliding..
my answer for the path is 2 as the block will be having some velocity at the point of leaving and path number 2 is showing exactly that path....
Thank you so much ashish sir..for evolving my mind to this level♥

[ABCDef-wj]

I think it should move along 2 paths as velocity of object = vel. w.r.t disk +vel of disk
There resultant will be along 2 path and since tangential velocity of disk is changing motion of object will also change in that direction

[anuragtewary]

Here is my analysis of last part: it moves through path 2.

(Complete analysis is done assuming block is not at the edge.)

As the block start moving, it does so radially outward wrt disk. Now as the disk rotates in clockwise sense, at every moment that the block slides along the line, there is some angular displacement in the clockwise sense. This implies, it cannot travel through path 1 or 4 as Sir mentioned (as in both cases, there is no angular displacement).

Now, it moves through either path 2 or 3. But it must be noticed, that the clockwise rotation is causing the curvature. While staying in contact with the disk, the object tries to have a straight line path, but there is another velocity (that of the disk) that moves it "up" (basically, rotates it clockwise). Hence it gets a clockwise curvature. (Outside the disk, its path is a straight line tangential to the point leaving the disk.

Hence my conclusions:
1. If the object were at the edge, it would follow path 1, but tangentially outward.
2. If the rotation were anticlockwise, it would follow path 3.
3. In current situation it would follow path 2.


If anyone has any question/dispute behind this analysis, kindly reply. It would be really helpful 😃

[sahilkamble]

Even aftet paying 30 to 60 thousand for my tuitions they cant even explain me in this depth and fundamental level of thinking. really we all students are so lucky to have a teacher like Ashish sir.
Happy guru pournima 😊 to Ashish sir and all PG team.

[gojousatoru]

9:43 sir the path traced by this object would most probably be the path 1 curve as the friction is acting opposite 2and 3 rd would certainly be not possible the path 4th is curved in outward direction which is possible only if the object was revolving in clockwise direction

[Yash-ktjv]

Yes sir 🙏I have solved even advanced level questions on circular motion and pyqs of advanced and nsep but did not think in this deeply manner. I request you to start explaining video format for some good conceptual tbt questions. This would be very helpful for all PHYSICS enthusiasts

[_justanotherhuman]

I don't if you noticed but this concept would be very easy if you just applied pesudo force in rotating frame in the dirn opposite to tengential acceleration

[dancingfairy]

Sir as per my understanding, block will move in path 3 becoz to leave the disk block will have to cover some distance radially for that it will take some time, it can't leave it instantly so in that period of time eventhough block is in contact with disk means a friction is still acting on it thus the line along which block will move wrt disk will shift from South West drxn to North West drxn that's why it will follow path 3.

[ravenking]

Sir according to me, it will go to path 3 in ground frame.
Path 1 and 4 isn't possible as the block has sliding tendency but the direction of its motion will still be decided by the friction of the disc.
For 2 & 3, at the moment when we increase the angular velocity of the disc, the new velocity of the block will initially have a tangential component only and the component of friction providing centripetal acceleration doesn't change. So the block goes through path 3.

[aayushshrivastava]

I think the path 2 will be correct

As the block slides, r increases so does the force due to increase in omega and centrifugal force. Hence, the block will accelerate in the direction of resultant force of the above mentioned forces untill it leaves the disc.... And when it leaves the disc it will stop accelerating and will move with a constant velocity ( not considering air friction for simplicity )


I am still not sure why the path appears to be curved as when block leaves the disc it should not be accelerating but the path says otherwise as the vector for position of block keeps changing

Help would be greatly appreciated

[SomethingUseful-sejf]

This literally was a part of my doubt last year . Most teachers whom I asked simply ignored it and said to memorize it .
Thanks to Ashish Arora sir for so much conceptual clarity ✨👍.

[aninditadutta]

Happy guru Purnima sir
Seeking your blessings 🙏
You are one of the best mentor in India
And I am very grateful that I found this channel and able to follow your advice .
From botton of my heart I thank you for your effort for us .

[jeeaspirant]

Is the path 1 right because in relative motion we give the component of velocity of the table to the block in the opposite direction thus after that we will find the component of blocks velocity and the velocity given opposite to the block which comes as 1 option

[rajatgupta]

Anwer may be path 3rd as we have to calculate w.r.t ground.
We use the concept of relative
.... Motion

[saurabhgyanani]

yes sir ye HC verma sir ne bhi exp. kar ke reason pucha tha apne schoolarship test me this year only

[ginger]

Path 3 will be correct for observation w.r.t. ground. 1 and 4 are obviously wrong because the disc is rotating clockwise and hence path cannot be in opposite sense. Path 2 implies that "friction" is increasing and not "angular velocity" opposite of which is path 3 which should be the correct answer.

[adarshkumarmeher]

The result direction of sliding with respect to ground (at an instant) of the block will be in the direction resultant of ( force of friction and centrifugal force ) at that instant
That is most probably it will follow path 2 .

[wahidzaman]

I think the answer is path 3. I compared the friction with gravity and the tangential velocity with velocity of an oblique projectile. The path 3 which is a parabola, should be trajectory w.r.t ground.

[quantumfreak]

Already knew all this....just came up to check if there might be anything i am missing out to learn more about friction....thank u very much sir❤