Author Topic: Physics help!  (Read 12019 times)

Offline @d!_†oX!©

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Re: Physics help!
« Reply #45 on: August 24, 2010, 10:23:47 am »
Ohh!! Thanks a lot Nid! The diagram made it so much easier :)

But hey wait, so what is the answer? :P
AAL IZZ WELL!!! ;)

Offline Vin

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Re: Physics help!
« Reply #46 on: August 24, 2010, 10:24:51 am »
Ohh!! Thanks a lot Nid! The diagram made it so much easier :)

But hey wait, so what is the answer? :P

yeah it did. :)

LOL!!

nid404

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Re: Physics help!
« Reply #47 on: August 24, 2010, 10:28:51 am »
Ohh!! Thanks a lot Nid! The diagram made it so much easier :)

But hey wait, so what is the answer? :P

LOL! A and B are out cause drag's not in the picture.

C is not possible  ::) If upthrust is greater, submarine is flung out of the water  ::)

So it's D.

Offline @d!_†oX!©

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Re: Physics help!
« Reply #48 on: August 24, 2010, 10:30:53 am »
Thanks once again Captain Nid ! ;)
AAL IZZ WELL!!! ;)

nid404

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Re: Physics help!
« Reply #49 on: August 24, 2010, 10:31:48 am »
Thanks once again Captain Nid ! ;)

At your service  :D

elemis

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Re: Physics help!
« Reply #50 on: August 24, 2010, 02:19:16 pm »
Cool, I was right :P

Offline MasterMath

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Re: Physics help!
« Reply #51 on: August 24, 2010, 03:56:05 pm »
I actually think there is a drag force .. but yeah D is the most reasonable one :P

Offline @d!_†oX!©

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Re: Physics help!
« Reply #52 on: August 24, 2010, 05:23:45 pm »
can someone help me in this question?
AAL IZZ WELL!!! ;)

Offline Vin

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Re: Physics help!
« Reply #53 on: August 24, 2010, 05:30:55 pm »
can someone help me in this question?

I'm guessing it's C. :-\

Offline Saladin

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Re: Physics help!
« Reply #54 on: August 24, 2010, 05:33:31 pm »
can someone help me in this question?

The answer is C.

The moments about a point is the force times he perpendicular distance.

Use trigonometry to find the length d.

Then you simply times this by 2N, to get the moments.

Then what you have to do is add the moments on the other side is also anti-clockwise.
« Last Edit: August 24, 2010, 05:38:24 pm by Engraved »

Offline @d!_†oX!©

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Re: Physics help!
« Reply #55 on: August 24, 2010, 05:39:28 pm »
I am not sure either...there are so many things in my mind right now, each leading to different answer..

1) It can be A:
                    Moment of a force = force X perpendicular distance
                    Moment of a force = 2sin50 X 0.15 = 0.23 Nm
2) It can be C:
                    Two forces acting simultaneously, thus two moments = 2 X 0.23 = 0.46 Nm
3) It can be D:
                    My book (International A/AS level Physics - CIE endorsed) says -
The torque of a couple is the product of one of the forces and the perpendicular distance between the forces
                   Therefore, according to this, Torque = 2 X 0.15 = 0.60 Nm

Fortunately, I don't have any idea about B, or else I'd be dead =.=
Someone please help me!!
AAL IZZ WELL!!! ;)

nid404

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Re: Physics help!
« Reply #56 on: August 24, 2010, 05:41:35 pm »
can someone help me in this question?

Force X perpendicular distance between the two forces

2sin50  X 0.3= 0.46Nm

C

Offline @d!_†oX!©

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Re: Physics help!
« Reply #57 on: August 24, 2010, 05:43:06 pm »
Oh I just realized, my 1) point is matching the 3) cause as the book says it is the perpendicular answer, so in that way 0.23 should be right.

Engraved, any say about my answers?
Ahana, the book says something else :/ it says only one of the forces..
AAL IZZ WELL!!! ;)

Offline Vin

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Re: Physics help!
« Reply #58 on: August 24, 2010, 05:45:20 pm »
Oh I just realized, my 1) point is matching the 3) cause as the book says it is the perpendicular answer, so in that way 0.23 should be right.

Engraved, any say about my answers?
Ahana, the book says something else :/ it says only one of the forces..

I saw the book too. Pg. 107. But a different kind of an example is given. What does the markscheme say?

nid404

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Re: Physics help!
« Reply #59 on: August 24, 2010, 05:46:43 pm »
Oh I just realized, my 1) point is matching the 3) cause as the book says it is the perpendicular answer, so in that way 0.23 should be right.

Engraved, any say about my answers?
Ahana, the book says something else :/ it says only one of the forces..

In a couple the magnitude of the force is the same.