Let us discuss skidding of an automoble while

taking a turn. Let us consider a circular track or we can consider that there is a straight

road on which a car is moving and taking a turn which is a circular arc of radius r . we

know that whwn a body is in a circular path just to maintain circular motion a centripetal

force is necessary or we can say that when a body is in a circular motion in a rotating

reference frame it experiences an outward centrifugal force.

Here this car was moving with a velocity v , when it takes a turn in a circle of radius

r we can say that in radially outward direction the car will experience a centrifugal force

m-v square by r and this centrifugal force will have atendency to skit the car in outward

direction on its wheel it will experience a friction in inward direction and if m-v

square by r is less than the friction then the car will take a safer turn it will not

skid. So we can state that for safe turning . without

skidding . the friction should balance m-v square by r and this friction should be static

friction . then only the car will be able to take a safe turn as the wheels will experience

an inward static friction and we can also say that for skidding. this m-v square by

r must be more than or=mu n that is the limiting value of friction , here we can say

that the normal reaction on car will be=to m-g.

we can also analyze this situation picorially here if we just draw the cross section of

the car . car will experience m-g in downward dierction on all of its wheel net normal reaction

will be in upward direction . car will experience a centrifugal force m-v square by r in outward

direction and its wheel will experience an inward friction which is balancing this m-v

sqaure by r, and at time of skidding the limiting value of this friction=mu n and here n=m-g

. so we can write this m-v square by r must

be less than=mu m-g. m cancels out. And we will get the value of speed=root of mu

r-g . so this is the maximum limit upto which , the car can take a turn without skidding

, if cars speed is more than or=root of mu r-g the car will skid . we can write here

for safe turning . speed of car must be less than root of mu r-g . this article you must

keep in mind, because this is important for various cases, whenever you will find a problem

in which an automobile is taking a turn. Now we will discuss skidding of an automobile

while taking turn on a banked road . in this figure you can see that a car is taking turn

on a banked road in this banked road for banking this

outer side of

road is slightly elevated up above the horizontal.

this elevation is provided because as we studied in the previous case that on a flat road if

we increase the speed of car then it will skid in outward direction , so on lifting

the outward edge in the upward direction we can say the road is banked and due to banking

the normal reaction is slightly tilted . Like if we take the cross section, this figure

is showing the cross section of this banked road. where this outer edge of road is elevated,

above the horizontal. such that the road is making an angle theta with the horizontal.

So in this situation.

the weight of car, m-g is acting in downward direction and if it is taking a turn in a circle of radius r , it

will experience an outward centrifugal force m-v square by r

in outward direction in rotating reference frame

Very well explaination !

Nice

sir here centripetal force is friction, for an observer in car centrifugal force acts but why these two forces are drawn in free body diagram with respect to observer

amazing explanation

sir why centrifugal force is acting on the car it should be experienced by the observor in the car ?

his hand writing is so fucking beautiful

how do we decide the direction of friction in horizontal circular motion?

Sir, in your books same examples are available in mechanics(2e) , because I not able to see the videos because I have to go to hostel

how the friction is acting inward please explain sir ..at 1:58

what a great video..after scratching my head for a long time this video helped me a lot..thanks for the video

sir if a car is moving along a circular path and suddenly the road became frictionless,then in which direction will the car move from the instant tangential or outward?

Sir u say centrifugal force acts on car equals to mv^2 /r… Why not u use centripetal force? Bcoz there is no discussion of interial frames…bcoz it depends on frame whether it will be centripetal or centrifugal firce…. can both terms be used interchangeably? Altleast in this ques? Plz do answer

sir if friction will get equal to the maximum value of limiting friction , why it will skid? it will just about to skid; but do not skid i think sir at time 9:46

Sir, we can make a simpler expression… if r = angle of repose = arctan(coeff of friction) and e the angle of elevation,

we can use tan (A-B) formula and say:

if v∈(sqrt(Rg tan(a-r)) , sqrt(Rg tan(a+r)) ), the car stays stationary in the plane of cross section of road.

(interesting>>)

One more thing, I've solved many problems where there are motion impending down or up an incline… I've observed that… ex… for force F so that a block is about to just move up/down a plane , the expressions of F for the other case can be found out by reversing the sign of coefficient of friction of the first case …

just like in the above case, +r can be replaced with -r and the meaning of the speed implies the opposite…

So, are there any counter examples to this observations? Also, can this be explained like… for the opposite kind of physical quantity (opposite in the sense that, the opposite of a minimum quantity is a maximum quantity at limiting condition of motion of body under friction) there can be assumed a world where, there is a frictional force that supports relative motion and for that case, coefficient of friction is -ve and the problems solved in such a world would give answers opposite to this world… and if this and that world have opposite meanings to friction, then the minimum of a physical quantity that has something to do with friction in that world is the maximum of that physical quantity in this world ?

sir what will happen if theta < angle of repose in last case 15:00 ?

I understood better in my class .sir please upload more videos

sir the direction of pseudo force is just opposite to the direction of acceleration

long hairs of hands!!!!!!!!!

super explaination ……

Jai Bhavani Jai Shivaji!!!!!!!!!!

Sir can u please guide me on the books whch i need to work to end up in iit.

I need an Explanation on why the centripetal force is acting away from the centre but not towards the centre

sir friction acts between the two surface in relative motion with each other but how can the friction act towards centre when the car takes turn bcoz according to definition it should act opposite to the direction of motion of car with respect to banked road which is at rest.

Sir, if I will concentrate on each and every topics, examples covered by you in these videos , Will I able to solve various problems related to Circular Motion . ( I had grasp each and every topics explained by you + examples) Hope you reply soon 💐👌👍

sir you said centrifugal force acting radially outward is psuedo force then how will it have tendency to skid the car

why static friction car i moving why not kinetic friction?

sir could you please tell me why roads are banked at the turning ?

Sir you are Ashish Arora sir(Allen)

Sir, In the last class if theta is more than angle of repose then skidding (downwards) will not occur??

for safe turning without skidding friction force f must be less than mv^2/R it should not be equal …….

sir cant we write the skidding will take place when velocity of car becomes root ugr

thus root 2a1S=root ugr therefore S=ugr/2a1 sir plzz reply i am very confused

Thik h

Sir can you suggest a book for jee main having medium no of problems but are standard & tough one

Nice explanation..

sir you are a very good teacher. crisp and clear explanation.

sir why is the direction of mv^2/r not along the surface and perpendicular to mg

Thanks for teaching me how to skid . I will use this concept to get involved in road accident…🤣

If pseudo force is not real force then how it made car to skid outward???

thank u so much sir

why car moving on circular path not bends towards center.

Thanks a lot ashish arora sir

Are you best teacher 👌👌👌👌

sir why does not centripetal force does not create non inertial reference frame

And centrifugal force create non reference frame why sir??

Please explain sir 🙏🙏

thanku sir… ap hum sabhi students ki bhaut hellp kar rhe he… there are very few people in this world as good and helpful as you are… You are helping us selflessly.

we are very lucky to have an amazing teacher like you.

thanku so much sir… you are a very nice person and best teacher.

God bless you and your family.

This helped me when nothing else seemed to. Thanks 😁

Ashis Arora are you fool you are illustrate and jahil

"HOW COULD YOU APPLY CENTRIFUGAL FORCE IN AN INERTIAL FRAME"

do you know the Definition of Centrifugal force

sir without any non inertial frame how are u taking centrifugal force………………………. please explain if we should assume the non inertial frame for circular motions by own if there it is not given ,……………………..i am getting confused…please explain

Car is in motion, so why static friction ?? Shouldn't it be kinetic friction ??

Sir in most books component of normal is resolved.is it correct to do so

You are really doing a great job.you have just , cleared all my questions on these topics. Thankyou for that.

Sir I have a doubt

If the car is exactly at the same speed which you mentioned in formula (10:50) It will skid or not???

thanks sir

🙏🙏

Sir, in first case of skidding of an automobile while taking a turn… U have found the speed wrt to observer in car??…(as u have solved it by centrifugal force)

In case 1 of banking why did u not take into account friction??

Why only if theta greater angle of repose as u have mentioned in the last

Albert Einstein rightly said "If you can't explain it simply you have not understood it well enough "

how the centripetal force is greater than or equal to frictional force?? If then frictional force is less enough to balance the centripetal force…..I think frictional force must be grater than or equal to centripetal force…..plz sir give me the explanation….

Sir,

Can you explain from inertial frame that how static friction provides centripetal acceleration??

(as given in ncert)

Please reply soon.

At 1:00 If car skids then in which direction it skids

According to observer on ground there will be no outward radial force so it should move in tangential direction

And according to observer in car it should move in outward direction it should move in outward direction due to centrifugal force

I am confused help me plzz

Wasn't centrifugal force an imaginary force, so how can friction act in response to it?

Is quegrid required for jee mains?? Sir plz reply

I can not understand why you show the direction of centripetal force to the outside…….

Disgusting..

centrifugal force is not a force at all, stupid explanation

it is centripetal force

Sir centrifugal force is applicable for person sitting inside car (non inertial frame of reference).but how can wheels skid by centrifugal force?

Very nicely taught.