ALL CIE PHYSICS DOUBTS HERE !!!

[missbeautiful789]

The turning effect of a Force is given by
Force x Perpendicular distance from the pivot

resultant torque= sum of clokwise moment - sum of anti-clockwise moments

Clokwise moments:
the 20N has a clockwise moment
20 x perp distance
20X3
clockwise moment=60 Nm

Anti-clockwise moments:
the 10N and 5N have a anti-clockwise moment, so
10N x its perp distance from pivot + 5N x its per distance from pivot
10X2 + 5X2
anticlockwise moment = 30 Nm

so resulant torque = 60 - 30
                         = 30 Nm

[Deadly_king]

The turning effect of a Force is given by
Force x Perpendicular distance from the pivot

resultant torque= sum of clokwise moment - sum of anti-clockwise moments

Clokwise moments:
the 20N has a clockwise moment
20 x perp distance
20X3
clockwise moment=60 Nm

Anti-clockwise moments:
the 10N and 5N have a anti-clockwise moment, so
10N x its perp distance from pivot + 5N x its per distance from pivot
10X2 + 5X2
anticlockwise moment = 30 Nm

so resulant torque = 60 - 30
                         = 30 Nm

Good job dear

Very informative explanation..........much appreciated

+rep after i spread the love

[TJ-56]

Thanx alot for the explanation, much clearer now
 can anyone help with this one

answers A
pls explain

[SpongeBob]

Total resistance= 7.5 ohms

Current flowing in the circuit= 2/7.5 = 4/15 A
Current flowing in each loop= 2/15

Voltage across each resistor= 5 X 2/15= 2/3 V

Across X (2 resistors) V= 4/3 V
Across Y (1 resistor) V= 2/3 V

Potential difference= Potential across X - Potential across Y= 4/3 - 2/3 = 2/3 V

[TJ-56]

Thank you Spongebob, much more clear now + rep ( i have to wait for around an hour though)
Got another question

The answer is C pls explain i tried everything, couldnt get to C
thanx in advance

[missbeautiful789]

We know that point X is a minmum point,

so thats suggests that the phase difference of the two waves at that point is 180 degrees, which is the same as half wavelength
so path difference=0.5 lamda

path difference = distance S₂ - distance S ₁ = 0.5 lamda

so ans is C

you need to understand that at ponit X. 1 wave is at its max and 1 is at its min to make a resulting displacement of zero.
that happens at a phase diff of 180 degrees, assuming that the both have same amplitude.

you might have said ans is D, but that is only correct if it is a maxima

[TJ-56]

thanx alot for the answer


the answers A
Can you please explain

[missbeautiful789]

This should answer your question. If it isn't clear let me know

http://i53.tinypic.com/jawhgp.jpg

You made a mistake RatJumper.  T₁ seconds after the ball is released the ball travels a distance of x, so you cant go and say that u=0 for the journey between time interval between T₂ and T₁, because it would have picked up speed when it reached point M₁

This is how i did it:



<a href="http://tinypic.com?ref=zxtfzm" target="_blank"><img src="http://i54.tinypic.com/zxtfzm.jpg" border="0" alt="Image and video hosting by TinyPic">[/url]

Distance to cover h given by area of trapesium

Distance=(1/2)(a+b)(h)
h=(1/2)(aT₁+aT₂)(T₂-T1)           
h=(1/2)a(T₁+T₂)(T₂-T1)            difference of squares so>>
h=(1/2)a(T₁²-T₂²)
2h/(T₁²-T₂²)=a

[$!$RatJumper$!$]

Thats right. Sorry about that guys.. my bad

[TJ-56]

thanx alot for the answer


the answers A
Can you please explain

can anyone help me with this ?

[Deadly_king]

can anyone help me with this ?

Moment of a force is defined as the turning effect obtained by the product of force to the perpendicular distance from a particular point.

Taking the pivot at the top of the ladder where it meets the wall.

Clockwise moments = Anti-clockwise moments
               Wa + Fh = W(2a)

NOTE : The perpendicular distance from the pivot to force F is h since the force is horizontal. The other force F being at the pivot has no component

[TJ-56]

Moment of a force is defined as the turning effect obtained by the product of force to the perpendicular distance from a particular point.

Taking the pivot at the top of the ladder where it meets the wall.

Clockwise moments = Anti-clockwise moments
               Wa + Fh = W(2a)

NOTE : The perpendicular distance from the pivot to force F is h since the force is horizontal. The other force F being at the pivot has no component

Thank you, +rep

[Deadly_king]

Thank you, +rep

Anytime dude

[WARRIOR]

Ok guys i need help in these , anyone who has time to spare !

A block of mass m1=3kg rests on a frictionless horizontal surface.A second block of mass m2 = 2kg from a cord of negligble mass that runs over a frictionless pulley & then is connected to the first block . The blocks are released from rest

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An idea of how it looks ^

QUESTION
(a) Find acc of the two block after they are releaased
(b)what is the velocity of the first block after 1.2s after the release of the blocks, assuming the first block does not run out of room on the table and the second block does not land on the floor?
(c)How far has block 1 moved during 1.2s interval?
(d) what is the displacement of the blocks from their initial positions .4 seconds after they are release?

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A rope is attached from a truck to a car of 1400kg.The rope will break if the tension is greater than 2500N.Neglecting friction , what is the max possible acceleration of the truck if the rope does not break.Should the driver of the truck be concerned that the top might break
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In a phys lab a glider is released from rest on a frictionless air track inclined at an angle.If the glider has gained a speed of 25 cm/s in travelling 50cm from starting  point , what is the angle of inclination of track

[$!$RatJumper$!$]

Could you tell which paper these questions are from? it would make it easier.