Recent content by MrB3nn

Thanks for your post dude, I see now. It worked, I checked with the divergence theorem and got same answer.

Homework Statement Hello, as part of a flux integral question in 3-d, I need to work out the equation of one side of a pyramid, of which the centre of the base is at the origin of the co-ordinate system. The points setting out the side I am considering are B(L/2,L/2,0) A(L/2, -L/2,0)...

Hi The rule you have broken is that x\sqrt{x} or x\sqrt{2} are not equal to x. They can't be simplified. They are what they are. The best you can do is write it in a different form i.e. x\sqrt{x} = x3/2 I think you have tried to take the common multiple out of the two terms as a factor but...

Thanks a lot for your help dude.

Ok I see. Thanks very much for your consistent help.

When I switch to spherical polars, r becomes r=r\widehat{r} and grad changes appropriately. For the div I get: Div = f(r) + rf'(r) and for the curl I get zero. I still can't see what this means. The div could be positive or negative depending on the actual function.

Ok, I did that using the correct formulae. Div: 3f(r)+x\partialf(r)/\partialx+y\partialf(r)/\partialy+z\partialf(r)/\partialz Curl: (z\partialf(r)/\partialy-y\partialf(r)/\partialz)i+(x\partialf(r)/\partialz-z\partialf(r)/\partialx)j+(y\partialf(r)/\partialx-x\partialf(r)/\partialy)k I really...

oh didn't realize this had posted, the site was crashing when I was trying to post. Well I know the field is always radial from the origin due to it's cartesian components. I also know the magnitude of the field will increase as you move in any direction from the origin. But in my mind, I...

More relevant equations (the site was crashing when I tried to put them all into one post): 5 \nablax(\Psiv)=\Psi\nablaxv+(\nabla\Psi)xv 6 \nabla.(v.w)=w.(\nablaxv)-v.(\nablaxw) 7 \nablax(vxw)=v(\nabla.w)-w(\nabla.v)+(w.\nabla)v-(v.\nabla)w

1. The problem statement, all variables and givenknown data Let r be a position vector from the origin (r=xi+yj+zk), whose magnitude is r, and let f(r) be a scalar function of r. Sketch the field lines of f(r)r Homework Equations 1 \nablax(\nabla\Psi)=0 2...

Homework Statement Let r be a position vector from the origin (r=xi+yj+zk), whose magnitude is r, and let f(r) be a scalar function of r. Sketch the field lines of f(r)r 2. Homework Equations 1 \nablax(\nabla\Psi)=0 2 \nabla.(\nablaxv)=0 3...

Yes that would be ok. In the example of a car, there will always be resistive forces i.e. friction/air resistance but if the driver accelerates enough to balance these, his speed will stay constant. If he turns the car there will be a static friction force directed towards the centre of the...

Think about the definition of velocity, being a vector. It has a magnitude and direction. Since centripetal and tangential acc'ns are at normals, you can have one without the other. A change in direction with no change in magnitude of velocity (speed) will give you a centripetal acc'n without...

By 'rotational inertia' I am assuming it means the moment of inertia of the body. Someone already told you the first part, that is basically using Newton II. Ignore the free body diagram initially for part one, think about translational movement only. For part two, you need the answer to...

Hello, This is not a 'homework problem' but I think it fitted more correctly in this thread than other more advanced ones. Basically, I am a first year undergraduate who did not study Chemistry at A-level. I am quite a serious student and I am trying to increase my background understanding of...