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05:08
@Abcd Three equation and three variable ,solve and eliminate
 
4 hours later…
09:06
@WrichikBasuIndian Thanks :)
@AakashKumar That's what I am unable to do.
@JohnRennie I have a question related to static friction.
Suppose I push a very heavy almirah
How can there be static friction because according to me the normal force does the "balancing work" @JohnRennie
@Abcd: hi
@JohnRennie Hey!
Static friction determines how much force you can apply before the object starts to move.
Once the object is moving you're quite correct that static friction then plays no part in the motion. Well, until the object comes to a stop again.
@JohnRennie No. How come there's friction when the object is not moving and I am applying force on it.
In such cases, there should only be Normal force IMO
@JohnRennie Have a look at this diagram:
@Abcd I answered a question on the mechanism of friction a while ago. Let me have a search for it ...
09:15
The almirah is not moving which I think is only because of normal force and not friction.
@JohnRennie ok
1
Q: How is frictional force dependent on normal reaction?

SwamiIt is a general concept that horizontal forces can only influence physical quantities along horizontal direction; similarly vertical force can produce acceleration etc. only along vertical direction. This is the same concept that helps us study projectile motion as a combination of two independen...

@JohnRennie Could you answer my question or does your linked answer address this issue too?
@Abcd Have a read through my answer to that question because it explains theorigin of the frictional force.
The answer has a missing diagram. Somehow the picture has got deleted. I'll see if I can get it back.
Ah, the picture is back now.
@JohnRennie yes
Read your answer.
What next?
Should I ask my question on SE?
@JohnRennie
It depends what you are asking.
What aspect of friction are you still not clear about?
09:27
@JohnRennie Did you see the diagram I posted? In that I do not feel that any friction gets developed :( because the force that the labourers exert is balanced by the normal force on them by the cupboard.
How can the two forces cancel each other? They are perpendicular to each other. They cannot sum to zero.
@JohnRennie Yes, they are perpendicular to each other and opposite in direction (so vector sum should be zero), aren't they?
@Abcd Yes, and two perpendicular forces cannot have a vector sum that is zero.
opposite in direction ???
Let me draw a diagram and send it to you.
b/w = between.
@JohnRennie Have a look:
Are you saying that Newton's 3rd law tells us the two forces are equal and opposite so they should sum to zero?
09:37
@JohnRennie Yes.
Ah. That's quite a common misunderstanding. In fact there have been questions about it on the site several times.
There are indeed two forces:
@JohnRennie Could you modify the original diagram using google draw and show me all the forces acting on the almirah and the forces exerted by the almirah?
1. the force exerted by the man on the cupboard
2. the force exerted by the cupboard on the man
yes
and they are antiparallel and equal, IMO
And Newton's 3rd law tells us these forces are equal and opposite
But the key point is that one is a force on the cupboard and one is a force on the man
The two forces are acting on different objects.
Suppose the man and the cupboard were floating in space - I suggest this so we don't have to worry about friction, gravity or any other forces.
09:40
I need diagrammatic understanding @JohnRennie :(
@JohnRennie yes
Imagine you're floating in space next to the cupboard, and you push it.
ok
The cupboard will accelerate in one direction and you will accelerate in the opposite direction. So the result of the pushing is that you and the cupboard start moving away from each other.
Does that make sense i.e. if you imagine yourself in space pushing an object what I describe will happen?
@JohnRennie No
Then we have a major conceptual issue ...
09:50
@JohnRennie Using Newton's third law? Yes it would happen.
Do you understand conservation of momentum?
@JohnRennie It's dealt with in later chapters.. haven't studied it yet.
 
9 hours later…
18:31
Can someone provide me with a hint to solve the problem below:
@Abcd give the full sum no.
And chapter no.
18:46
@WrichikBasuIndian Page 98 question 16. Friction
@WrichikBasuIndian I just wanted a hint
@WrichikBasuIndian Are these available for free or have you bought them?
@Abcd free
@Abcd they're adding more chapters.
@WrichikBasuIndian That's really kind on their part though the accent can be better. Like Galaxy lectures have a global accent option.
Go to you tube and search for Omega Open Course.
18:55
@WrichikBasuIndian Thanks.
@Abcd I don't hear the voice. The animation works more than enough.
@Abcd you're welcome :-)
@WrichikBasuIndian Oh, I see.
@WrichikBasuIndian Which chapter are you on?
I'm doing work power energy, but I left circular motion to keep up with school.
Which board?
18:57
I am in an ISC affiliated school.
@WrichikBasuIndian Same here.
English is tough man @WrichikBasuIndian
How much did you score in tenth(icse)?
@Abcd my school gives huge notes in each chapter. I just mug up and write.
@Abcd 95%.
@WrichikBasuIndian You are lucky.
@WrichikBasuIndian Best of 5?
@Abcd don't know so much. forgot.
Got a 100 in computer. :)
@WrichikBasuIndian Best of 5 means average score of 5 highest scores
@WrichikBasuIndian Same here! :D
I got 91 in English which ruined my percentage :(
@Abcd I got 89.
19:02
I got 97.4 percent in total with 100 in HCG too :)
@Abcd baba re.
@Abcd salute.
@WrichikBasuIndian Lol
How did you memorise so much?
I was so frustrated that I did maths and physics from 11 all during the exam. Also a bit of QM.
@WrichikBasuIndian Man I worked damn hard. This score just can't reflect the amount of hardwork I put in...I was expected to get above 98% by my teachers
@WrichikBasuIndian DIdn't get you. What do you mean?
@Abcd I studied out of Syllabus all during the exam. I never like being cocooned in the syllabus.
19:05
Oh, I see.
QM is Quantum mechanics.
Well done!
@Abcd no, this world wants marks more than knowledge. A better well done to u :-)
@WrichikBasuIndian Replace "this world" with "India"
@Abcd perhaps. America doesn't have any education system at all. Indian one needs to be modified. I've written a good long article on that.
19:08
@WrichikBasuIndian hmm
@WrichikBasuIndian I didn't understand the direction of friction in that video
@Abcd how will you define "syllabus" if asked?
@Abcd ohhh, that one. Post a comment below.
@WrichikBasuIndian Content that students are supposed to study.
@WrichikBasuIndian What do you mean?
@Abcd my definition: "minimum amount of knowledge a person of a particular class must have before going to the next. It defines the lower limit, not the upper."
True.
@Abcd if you can't understand anything, post a comment below. They'll answer it soon.
19:13
@WrichikBasuIndian My question has already been asked 7 months ago. No one answered it :p
Read the last comment
@WrichikBasuIndian I got my answer here: quora.com/How-does-friction-work-when-we-walk-or-run
@Abcd then that question is faulty.
@WrichikBasuIndian It's not. It was a valid question.
@Abcd OK, the quora one explains good.
Good to find an ISC mate here @WrichikBasuIndian . Stay connected!
bye @WrichikBasuIndian Ttyl
@Abcd good night!

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