GOTW: Sciene and tech game - Page 6

bhopalyellow

@bhopalyellow

Senior Member

Posted: 15 years ago

This value is more than 1N, applied force

So the friction force will adjust itself to 1N and the Book will not move and remain stationary

So value of friction force= 1N and direction opposite to applied force

rajnish bhaiya/akhl bhaiya.......plz wud anyone of u explain this last part of the question...i'm not getting it.....😕

Edited by bhopalyellow - 15 years ago

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343707

Inactive

Posted: 15 years ago

This content was originally posted by: bhopalyellow

This value is more than 1N, applied force

So the friction force will adjust itself to 1N and the Book will not move and remain stationary

So value of friction force= 1N and direction opposite to applied force

rajnish bhaiya/akhl bhaiya.......plz wud anyone of u explain this last part of the question...i'm not getting it.....😕

ops by mistake i had written less in place of more so plz edit ur quote

let me explain

static friction has a maximum value. this friction acts when the body is stationary. static friction varies accordind to force applied. unlit maximum value is reach which is uN the value of static friction is equal and opposite to force applied and it keeps the object stationary. when the value of force exeeds this maximum value the static friction changes into kinetic friction whose value is slitely less than maximum static friction and remains equal to ukN(uk=coefficent of kinetic friction).

I think you got it if not then tell i will explain you in detail😛

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akhl

@akhl

IF-Rockerz

Posted: 15 years ago

Jasleen,

Maximum value of static friction = coefficient of static friction * normal force

Here coefficient of static friction = 0.2

and normal force = 10 N

Therefore coefficient of static friction * normal force = 0.2 * 10N = 2 N

But note that this is the maximum value of static friction. Actual value is equal to this or less than this. If any less value is enough to stop the book from sliding, then static friction is as much as is needed to stop the book from sliding.

I push the book with 1N. This means that if table applies 1N force in opposite direction, then it is enough to stop the book from sliding. So static friction = 1N.

_____________________

Suppose I change the question a little bit.

I push the book with 3N force. Other data remain as earlier. Do you know what will happen in this case?

Note: This question is not a part of the game. So no points on it. So do not worry whether your answer will be right or wrong. It is only for your learning.

Edited by akhl - 15 years ago

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bhopalyellow

@bhopalyellow

Senior Member

Posted: 15 years ago

thank u rajnish bhaiya and akhl bhaiya....actually i got confused with that word 'less'.....and the 2nd half.....coz when i calculated even i got it correct till 2 N with the same formula...but it's all clear now....thank u both of u😃......and i have edited my quote rajnish bhaiya.......waiting for more good ques. from both of u.............😛 Edited by bhopalyellow - 15 years ago

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akhl

@akhl

IF-Rockerz

Posted: 15 years ago

Jaslees,

I edited my explanation and in the end, have added a question. It is only for your learning. Can you tackle that? And also please try answering the following question. This is also not a part of the game but only as learning exercise.

A book is kept on the table. Both are moving towards north. Table is moving at 2 m/s and book is moving at 1 m/s. Both these values are relative to ground.

What is the direction of force of friction on the book?

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343707

Inactive

Posted: 15 years ago

oops i thought this que is part of game and answered. but this is for jasleen. so edited😃😃

Edited by rajnish_here - 15 years ago

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bhopalyellow

@bhopalyellow

Senior Member

Posted: 15 years ago

This content was originally posted by: akhl
Jasleen,
Maximum value of static friction = coefficient of static friction * normal force

Here coefficient of static friction = 0.2

and normal force = 10 N

Therefore coefficient of static friction * normal force = 0.2 * 10N = 2 N

But note that this is the maximum value of static friction. Actual value is equal to this or less than this. If any less value is enough to stop the book from sliding, then static friction is as much as is needed to stop the book from sliding.

I push the book with 1N. This means that if table applies 1N force in opposite direction, then it is enough to stop the book from sliding. So static friction = 1N.

_____________________

Suppose I change the question a little bit.

I push the book with 3N force. Other data remain as earlier. Do you know what will happen in this case?

Note: This question is not a part of the game. So no points on it. So do not worry whether your answer will be right or wrong. It is only for your learning.

ans. : as u explained that the min. force which can stop the book from sliding is the required force , so the min. force here is 2N , although the book is pushed with 3N but the min. force is 2N which is enough to stop the book from sliding , so the ans. is 2 N .

PLZ PLZ BHAGWAN KE LEYE KE DIJEYE KI YE ANS. SAHI HAI...WASE WRONG HAI TO BHI MUJHE PATA CHAL JANA CAHIYE KI MEIN KETANE PANI MEIN HOON.....THANKS FOR THIS QUES. BHAIYA.....😃😃😃

I'LL TRY TO SOLVE THE OTHER ONE ALSO....😊

Edited by bhopalyellow - 15 years ago

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bhopalyellow

@bhopalyellow

Senior Member

Posted: 15 years ago

😊

Edited by bhopalyellow - 15 years ago

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bhopalyellow

@bhopalyellow

Senior Member

Posted: 15 years ago

[quote=akhl]Jaslees,

I edited my explanation and in the end, have added a question. It is only for your learning. Can you tackle that? And also please try answering the following question. This is also not a part of the game but only as learning exercise.

A book is kept on the table. Both are moving towards north. Table is moving at 2 m/s and book is moving at 1 m/s. Both these values are relative to ground.

What is the direction of force of friction on the book?

[/quote]

i think.......the relative speed=speed (moving table - book)

=2-1 = 1 m/sec.

and as the friction opposes the force on the book and the force is in north direction so the friction will be in opp. i.e., south direction........😊

Edited by bhopalyellow - 15 years ago

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343707

Inactive

Posted: 15 years ago

untill here you are corect jasleen. the force of friction is 2 N. but question is not solved completely. you need to calculate acceleration too. so try to calculate acceleration😊

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