If you are using centrifugal anything before university physics, you should stop. Just use an inertial frame and solve things without using that.

@naturallyInconsistent It wouldn't hurt to know how to solve using centrifugal and centripetal force.

There is no such thing as centrifugal force. It is strictly a fictional effect that comes from the use of non-inertial frames, and is causing too much confusion with students.

But how else would one solve a problem like the one I mentioned: A particle is left from the top of the circular track. find where it loses contact?

By doing it properly. Only need to consider what centripetal acceleration requires things to be, and doing a test on the normal reaction force. There is only one way to get a logically acceptable answer using purely Newton's Laws in this inertial setting, and it will always get the correct answer.

2 things. First I am working on the Work and Energy chapter, so, newton's laws should have the least usage in this problem. Second, I still didn't get what you mean by " Only need to consider what centripetal acceleration requires things to be"

I have no idea why anybody would want to teach work and energy before Newton's Laws, seeing that 1) Newton's Laws are conceptually easier to teach and 2) solves many problems that energy alone cannot and 3) is usually the reason to motivate the consideration of energy, rather than the other way around, or some 3rd party move.

No, ive done newtons laws of motion

i meant that the problem is supposed to be solved with work energy, and not newtons laws to give more practice

That is a most bizarre misunderstanding. If you have already done N2L, then you should be expected to use N2L when required. This problem has a bit of stuff that can simplify your argument if you use energy, but it will require the use of centripetal acceleration, which is a N2L topic.

i.e. it is an AND question, not a OR question. You cannot choose to only use energy.

ya ofc, i said we had to minimise the use of nlm

thats the point of work and energy, isn't it?

No. Energy is an organising principle from which we understand our universe in its own right. It is just so happens that Newton's Laws is the correct introduction to young students.

not to offend you, but why does that seem more philosophical than physical?

also, this is very apart from my question

Because if you learn enough physics, there is a lot of philosophical views to make sense of the whole structure.

I am not at all interested in solving just your single one question.

okie, i get the fact that i should use nlm in inertial frames, but why and where am I going wrong

For your question, you can use energy to quickly supply the variables you need for the centripetal acceleration calculation.

but if you see walter lewin's lectures, he says that centrifugal force is a very real thing

he just seems to like and use it more than centripetal force

You are wrong because there is no logical step that you could get anything correct by throwing centrifugal anything with gravity.

wdym

No, I have watched the entire set of Lewin's lectures and I am not at all able to remember when he used centrifugal anything.

i just saw it

wait

He only said that you feel it in your bones that there is a centrifugal effect

But that is an illusion.

But that is beside the point. If you are not yet in university physics, you should not be using centrifugal for anything

As long as you have not yet derived the maths of centrifugal, Coriolis and so on, you are in no position to argue using them correctly. Wayyyy too easy to make mistakes.

fyi, indian exams are just annoyingly equal to university physics

also

ik that centrifugal force is a psuedo force

and it works just as well if used properly

also, i kind of like it, since it worked for me in each case except this one

Well, I have helped enough Indian students myself and I am not willing and able to continue helping any student who insists in using centrifugal effect when they are clearly not yet able to deal with it.

the max height needed to release a particle which will complete a circle in a track (like the hotwheels ones)

is 5/2 of the radius of the circular part of the track

now here what i would do is equate the centrifugal force with gravity at the top most point

and then figure the mathematics out

now specifically, where am i going wrong

??

It does not seem like this is a hotwheels track type question.

hi

i meant that the particle is on the inside of the circular track

not outside

because the hotwheels cars travel inside the track, duh

If it is inside, then trying the centripetal = gravity trick could work. But this does not seem to be that.

in this specific problem its outside the track

ik @tensorman666, but he is trying to explain something else

Also, it is centripetal = gravity, not centrifugal = gravity

wait, explain that

I am not trying to explain something else; you asked something else here and I am not sure what it is you want

Explain what?

centripetal = gravity, not centrifugal = gravity

this thing

bcs walter lewin explained it with centrifugal force ig

at the topmost point, you can find the velocity by WPE and then you just see that there are no horizontal forces acting on the thing at the topmost point so the total force is just mg-N

then you equate it to the centripetal force

then you get the answer

which is the centripetal force

Ok, sure. When you have the hotwheels situation, the top of the track is curving downwards. Gravity is pointing downwards, centripetal direction of the top of the track is also downwards. If you want to do any equalisation, you use centripetal = weight. Centrifugal would be the opposite direction.

wont the normal be equal to mg - Fc?

wait

yes but thats not what we want

2 people chatting is tough

we want the total force right? its mg-N them

yes but the answer

@tensorman666 yes, this is far better

but then you require a force for accelarating the block in a circle

which is mg-N

is not that

the answer which everyone is saying is just Fc

ok so what

look at this

dont mind the accent

just part b

you should know that the centripetal force is not something which exists independently as its own in nature like gravity or nuclear forces. The centripetal force is provided for by other forces acting on the object

so as to move it around it a circle

think it like this:

at the topmost point the block is undergoing accelaration given by v^2/r due to virtue of its circular motion right

yup

so the total force acting on the object =ma=vv^2/r

m*v^2/r sry

which is the centripetal force

did you get it/

total force is Fc

yep

what abt gravity

bruh

look at what i said earlier

mg-N PROVIDES the centripetal force

ooh

I will leave you with Tensorman666. He is saying all the correct things and it is clear that he knows what he is saying and giving you good help.

so my analogy N = mg -Fc is mathematically correct, but psychologically flawed?

Yes

but then wth did i get correct answers for the previous problems

which grade are you in

like the one asking for the minimum velocity of the pendulum to complete a circle

you are a jee guy right>

ya

11th grade?

10 actually

nvm, for the minimum velocity thing for pendulum you can do the same thing

There are situations whereby your trickery could work; it is just not a coherent way to work things out. It is a cheap way to get a specific scenario, but it is not a full framework to solve problems like N2L is.

T+mg provides the centripetall force

i think its best to work in inertial frames, centrifugal force is a slippery concept

justa second

It is far more important to learn a full framework that will always work, rather than specific tricks that only gives you the correct answer in specific scenarios.

but there i said that T must be equal to zero at the top point for the circle to be complete

im curious, did you skip the derivation of the centripetal force expression?

I feel like that is central to our discussion here

not really

but it is a part which i don't really remember well

like i remember the coordinate geometry part

which state u from

coz imma 10th grader myself ;)

but i dont really know the intuitive explanation of Fc

well, all over, like born in delhi, rn in kolkata, and parents from lucknow and bangalore

for that refer to the geometric derivation for intuition

it uses a cool sinx/x limit

you will get your intuition

did you give IOQM last year

isnt it like that where they approximate the position triangle for the velocity triangle??

yes

qualified for RMO?

but culdnt qualify for inmo

ya, rmo gave the paper, like cut off was low only

how much u got

im rmo

i got like 8

;9

lower than my expectations

thats al

thats what matters

nice talking t you and bye!

gotta sleep

7 hours

mom?

she does that with me too

will kill me if i dont go to sleep rn

bye1

i understand

bye