# Search results

1. ### Some questions regarding EMC

The main subject of it is about cable shielding in electromagnetic compatibility. I've googling myself but nothing much info about it. I got some answers from german , after translate is something like this ( dotn know correct or not ): 1. reflection produces ripples 2. to against strong...
2. ### Some questions regarding EMC

thanks for the reply , I really need to know why lamda >> L .. pls help
3. ### Some questions regarding EMC

HI, I got some questions regarding Electromagnetic Compatibility: 1. When we measure transfer impedance for cable shielding , why we have assume that lamda >> L ? 2. What is the difference between trasnfer impedance & admittance? My friend told me that the impedance in purely...
4. ### Material to dissolve enamel paint

hi, I spray with my keyboard with Spray paint ( i think is enamel paint ) and now i am regret - so i need a solution to dissolve it but i can't remember the name , can anyone tell me ? thanks
5. ### Energy is conserved ?

energy is conserved ??? hi, just read about energy conservation but i am not so clear about it .for example : a particle moves in uniform oscillation electric field - does the energy conserved ? what is the criterion for conservation energy? thanks
6. ### Potential conserved quantities

So i am correct ?? angular momentum of z and energy are conserved ?
7. ### Potential conserved quantities

no i am not familiar to Langrage mechanics - will learn next 2 months
8. ### Potential conserved quantities

My thought : angular momentum of z component and the energy of the system is conserved ... Pls tell me if there are more quantities are conserved thanks
9. ### Potential conserved quantities

hi, if i have mass possess potential U(x)=-Gm1m2/(x^2+y^2+(kz)^2 )^1/2 , i said angular momentum of z is conserved but not angular momentum of x , y .. is it correct ? what else is conserved ? energy ?
10. ### Projection with coriolis force

hi, i read lots of book regarding fictitious force - coriolis and centrifugal forces, but i am not clear how to determine the direction of the force.. example. if we throw a ball vertical up , how we can know the deviation from the original position ( from book we know that if the ball...
11. ### Motion of spring mass with charge in magnetic field

ya, i dont know is right or wrong - dv/dt= qBv/m -kx but the spring's motion is in x y plane ( if z is magnetic field) - how can i decribe the force cause by spring ?
12. ### Motion of spring mass with charge in magnetic field

hi, got a difficult question to ask : we can easily find the motion of charge in magnetic field.But now if the charge is attached to a spring, how can we find the general motion ? is it like a gyroscope ? thanks
13. ### Are you in inertial frames?

Thanks for the reply -- i am clear now thanks
14. ### Centripedal & Centrifugal force

yes, centrifugal forces and coriolis forces are called Fictitious force..
15. ### Centripedal & Centrifugal force

hi, what is difference between Centripedal & Centrifugal ? One is in inertial frames and the other in rotating frames? one is 'true' force and the other is fictitious force? thanks
16. ### Are you in inertial frames?

but his question is : How to determine that your lab is in inertial frame or not ?
17. ### Are you in inertial frames?

Are you in inertial frames??? hi, today my friend ask me 2 simple questions, too shame i cannot answer him...so i post it here: is the classroom an inertial system ?? earth is rotating around the sun - so ...can still consider as inertial ? 2. If u working in laboratory to find so...
18. ### Vertical Projectile with air friction

i will consider both conditions .. if the initial velocity is not too high - then is propotional to v , if not ( high velocity ) then is proportional to v^2... i got a long a strange solution for max height...
19. ### Vertical Projectile with air friction

i had the same equation motion, but how we can find the max height ?
20. ### Vertical Projectile with air friction

hi, If we throw a ball vertical upward, we can easily find the maximum height if ignore the friction.. So if we switch on the friction, how can we find the max height ?

22. ### Kernel of differentiation and integration

nevermind - i think i konw the answer
23. ### Kernel of differentiation and integration

hi, i got a algebra question regarding kernel 1.what is the kernel of intergration operator: T(p)= p'(x)? 2. what is the kernel of differentiation operator : T(p) = integration of p(x) from -1 to 1 thanks
24. ### Use identities to Prove linearly idenpendent

that mean any set of vectors contain a 0 cannot be linearly independent ? not independent but linealy independent
25. ### Use identities to Prove linearly idenpendent

determine following setd of vectors in F(-infinitity, infinitiy) are linearly independent (using appropriate identities) 0, [cos (pi*x)]^3 , [sin 3*pi*x]^5 pls help !
26. ### MATLAB Determine the machine precision in Matlab

hi, how to determine the machine precision in matlab and estimate from this how many bits are used in the mantissa ??
27. ### 2 simple vector spaces question

( a 1 ) --- is this 2x2 matrix a vector space ? sorry for asking this coz this is abstract 1 b me
28. ### Linear (in)dependent vector sets

how i use the identity to solve that problem
29. ### Linear (in)dependent vector sets

are 6, 3*(sinx)^2 and 2*(cosx)^2 - linearly independent ? Can someone explain how to determine it ?
30. ### 2 simple vector spaces question

so you are saying that : the set of all positive real numbers with operations x+y =x*y and kx=x^2 are vector space?