Recent content by Niishi

Homework Statement A particle of mass m moves in one dimensional such that it has the Lagrangian L=\frac{m^2\dot{x}^4}{12} + m\dot{x}^2V\left(x\right)- V^2\left(x\right) where V is some differentiable function of x only. (i) Find the equation of motion for x(t) (ii) Find an...

Thanks mathwonk i was able to get it. I did not understand the explanation in the second the post particularly why t has been introduced etc.

Hello, Can anyone please tell me how to get the relationship between partial derivatives at a point, that is, dy/dx|x = - df/dx|y / df/dy|x ?

I thought if charge density was a function of r it would be given as such. Yes I am wrong. I should not multiply by the angle because the angle is not a length... the length is r dpheta. thank you.

Actually by 2 pi^2 i think.

If you had to find the electric field inside the spherical charge distribution and charge density depended only on r then you would consider a gaussian surface inside the spherical volume. To find the charge enclosed you would need to integrate change density rho(r) from r=0 to r=radius of...

If it is a spherical distribution and charge density depends on radial distance the field lines would be symetrical so you can use Gauss law.

No. I am saying its right ... but u said that the normal force varies i wanted to add that it is equal n opposite to the force that the object exerts on the surface. So u knew that i think?

The normal reaction force of the surfce on the object is equal and opposite to the force exerted by the object on the surface which in this case is not mg but mg - F sin 30.

Hello.I can't follow your answer what is N? But friction is Mu times the reaction which is mg - sin 30. F cos 30 is in fact greater than mu times mg- sin 30.Therefore object moves.Hope it is of help.

I find that particularly true for me for exams.