Seemingly wrong answers in QK Ghori
 

Hi,

First two exercise questions of QK Ghori Chapter 5 - Friction.

1. The answer is written as [B][length of laddder] [/B]X [B][Coefficeint of Friction][/B] X [B][Cotangent of Alpha]. [/B]

When i solve it, the answer is [B][length of laddder] [/B]X [B][Coefficeint of Friction][/B] X [B][Tangent of Alpha]. [/B]. No way can i get cotangent there.

2. For question two again using the same concept, there appears Cotangent in the answer whereas I get [COLOR="Lime"]Tangent. [/COLOR]

Compare these two question to Example 4 in QKGhouri. The comparison shows the solutions will yield Tangent in the answer and NOT Cotangents.

Can any one cross-check please ?

Br,

[QUOTE=Roshnain Swati;756207]Hi,

First two exercise questions of QK Ghori Chapter 5 - Friction.

1. The answer is written as [B][length of laddder] [/B]X [B][Coefficeint of Friction][/B] X [B][Cotangent of Alpha]. [/B]

When i solve it, the answer is [B][length of laddder] [/B]X [B][Coefficeint of Friction][/B] X [B][COLOR="Red"][Tangent[/COLOR] of Alpha]. [/B]. No way can i get cotangent there.

2. For question two again using the same concept, there appears [COLOR="Red"]Cotangent[/COLOR] in the answer whereas I get [COLOR="Lime"]Tangent. [/COLOR]

Compare these two question to Example 4 in QKGhouri. The comparison shows the solutions will yield Tangent in the answer and NOT Cotangents.

Can any one cross-check please ?

Br,[/QUOTE]

hopefully will let you know by 8 or 9. have you done virtual motion?

[QUOTE=Roshnain Swati;756207]Hi,

First two exercise questions of QK Ghori Chapter 5 - Friction.

1. The answer is written as [B][length of laddder] [/B]X [B][Coefficeint of Friction][/B] X [B][Cotangent of Alpha]. [/B]

When i solve it, the answer is [B][length of laddder] [/B]X [B][Coefficeint of Friction][/B] X [B][COLOR="Red"][Tangent[/COLOR] of Alpha]. [/B]. No way can i get cotangent there.

2. For question two again using the same concept, there appears [COLOR="Red"]Cotangent[/COLOR] in the answer whereas I get [COLOR="Lime"]Tangent. [/COLOR]

Compare these two question to Example 4 in QKGhouri. The comparison shows the solutions will yield Tangent in the answer and NOT Cotangents.

Can any one cross-check please ?

Br,[/QUOTE]

your answer is correct but so is the book. you are taking alpha with the horizontal, he has taken alpha with the vertical. he has written in the answer of Q1 that alpha is the inclination with the vertical. why? ghori knows :)

Ahaan.. I didnt read that extra line that Alpha was with vertical. --- And i dont know why he did that..Khair.... Thank you.

I am doing randomly. This is an easier chapter so what to get some consoler type questions. Will do virtual motion after this. I had a glimpse and i feel thats doable.

[QUOTE=Roshnain Swati;756392]Ahaan.. I didnt read that extra line that Alpha was with vertical. --- And i dont know why he did that..Khair.... Thank you.

I am doing randomly. This is an easier chapter so what to get some consoler type questions. Will do virtual motion after this. I had a glimpse and i feel thats doable.[/QUOTE]

ok. another thing though: have you been able to solve exercise of 12?

I will not be doing that I think.

I am done with Friction part - a good chapter i would say. Will do virtual work tomorrow onwards.

And i have not even started EDS, Pak Affairs, Islamiat, Psychology and Current Affairs - The challenge is an enormous one but I think these are doable. Maths has been time consuming -- Lets see what happens. BTW, how long will EDS take me given i have an engineering background ?

@Roshnain Swati

Red font has been and continues to be reserved for moderator use. Avoid using it.

[QUOTE=Roshnain Swati;756662]I will not be doing that I think.

I am done with Friction part - a good chapter i would say. Will do virtual work tomorrow onwards.

And i have not even started EDS, Pak Affairs, Islamiat, Psychology and Current Affairs - The challenge is an enormous one but I think these are doable. Maths has been time consuming -- Lets see what happens. BTW, how long will EDS take me given i have an engineering background ?[/QUOTE]

I think EDS should not take more than a week for you.

and you began preparation before feb 2014 didn't you?

and please, do write a paragraph about virtual motion here. i could not understand what virtual motion is all about. i did not do it last year.

regards

No- I didnt start preparing then - It was on and off visit to cssforum.. First I thought i would go with IndoPak - collected few materials and then put a halt to it once i read the Tughluq stuff. Am doing a job too - So my studies have been on and off - All i have been able to do are few chapters of mathemathics - tensors, vectors, few from mechaniscs, few topics from DE -- I ve opted Psychology which is interesting and provides some impetus. I have not started Essay and its cousin Precise - but i think Precise is passable -- Much work remains - The real momentum does not exist since the CSS stuff is not my craze - Am doing it for the sake of challenge. :)

And I will write few lines about virtual work but going to listen to Imran Khan now.

Ya Allah IK ka kuch kar le please, taakay log apnay kamo mein mashghool ho jain aur hamamri apllied maths section ki virtual motion chal paray...