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rajnish kumar

@_rajnish_

Inactive

Posted: 17 years ago

#41

hey guys i am getting confused as members are giving points to answered question as well. so untill now i will calculate all points and from next time the points of first answer will only be calculated so final score is
Akhl-40(assuming godison gave you 5 point)
Rajnish-30(assuming sita di gave me 5 points)
bhopalyellow-9
sita-14
tan-5
godison-9

Edited by rajnish_here - 17 years ago

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akhl

@akhl

Dazzler

Posted: 17 years ago

#42

Rajnish,

Your answer to the friction question is correct. So 5 points to you.

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akhl

@akhl

Dazzler

Posted: 17 years ago

#43

Following questions are yet to be answered: -

1. From Jasleen - What kind of drugs are used in medicines?

2. From Rajnish - What is the difference between hydrogen bomb and atom bomb?

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akhl

@akhl

Dazzler

Posted: 17 years ago

#44

@godisone,

Your question "what is the atomic mass of Palladium?" has been answered. Please give points.

@Sita,

Your question "what is the Lanthanide series?" has been answered. Please give points.

@Rajnish, see if you need to update marks after godisone and Sita award points.

@All,

Now onwards, please award points only to the first person who gives correct answer. If you find that a question has more than one part and different members have answered different parts so that combining the answers makes complete answer, then you may split points between them. But if anybody gives complete answer, then give marks only to the first person who gives complete answer.

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akhl

@akhl

Dazzler

Posted: 17 years ago

#45

Originally posted by: rajnish_here
what is the difference between hydrogen bomb and atom bomb?

In hydrogen bomb, fusion reaction is used to create the main explosion. Fusion is the reaction in which two smaller nuclei combine to form a larger nucleus. In the process, large amount of heat is released. The nuclei, which combine in hydrogen bomb are deuterium (isotope of hydrogen having 1 neutron) and tritium(isotope of hydrogen having 2 neutrons).

The fusion reaction requires two nuclei to combine. Nuclei are positively charged. So they repel each other. Therefore, external energy is required to make them combine. The energy is supplied by detonating a small atom bomb and atom bom involves fission(as explained below). Thus hydrogen bomb involves both fusion and fission. But fusion causes main explosion. Fission is used to trigger fusion.

In atom bomb, fission reaction is used. In fission, an unstable heavy nucleus is split into smaller nuclei and large amount of heat is released in the process. The nuclei, which are used in atom bombs are isotopes of uranium(U-235) and plutonium(Pu-239).

Note that the concepts of fusion, fission, atom bomb and hydrogen bomb are much more detailed. But I have only talked about the difference between hydrogen and atom bombs because that is what the question says.

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akhl

@akhl

Dazzler

Posted: 17 years ago

#46

So now one unanswered question: -

1. From Jasleen - What kind of drugs are used in medicines?

Somebody please answer the above question.

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rajnish kumar

@_rajnish_

Inactive

Posted: 17 years ago

#47

avinash,
while counting the point i have assumed godison has given you 5 points and sita di has given me 5. If latter they give different point I will edit my point update.
your answer is correct and detailed so 5 point to you. your total now become 40
I don't know ans of jasleen, hope someone else can answer

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akhl

@akhl

Dazzler

Posted: 17 years ago

#48

Next question from me: -

A book is kept on a table-top, which is horizontal. Coefficient of static friction between the book and the table = 0.2

Weight of the book is 10 N. Thus normal force from the table = 10 N.

The book is pushed with a horizontal force of 1 N. What is the magnitude of the force of friction by the table on the book? No need of FBD. Just show the calculations and the final answer.

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rajnish kumar

@_rajnish_

Inactive

Posted: 17 years ago

#49

Originally posted by: akhl
Next question from me: -

A book is kept on a table-top, which is horizontal. Coefficient of static friction between the book and the table = 0.2

Weight of the book is 10 N. Thus normal force from the table = 10 N.

The book is pushed with a horizontal force of 1 N. What is the magnitude of the force of friction by the table on the book? No need of FBD. Just show the calculations and the final answer.

Lets calculate

Maximum value of static friction =uN

Where u= coefficient of static friction

N= Normal reaction

Here u= 0.2 and N=10

So maximum value of static friction=0.2*10= 2N

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

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