Recent content by kudoushinichi88

Terribly sorry, I should've made my question clearer. All of the ps in my post refers 4-momenta while \vec{\textbf{p}} refers to 3 momenta. I'm working in the CM frame. In this scattering reaction the subscripts refers to the particle in the reaction as follows: 1 + 2 -> 3 + 4 @andrien, you...

Homework Statement For a scattering problem A + A - > B + B in the Toy Theory, Need to show (p_4-p_2)^2-m_C^2c^2=p_4^2+p_2^2-2p_4\cdot p_2 = -\vec{\textbf{p}}^2(1-\cos\theta)Homework Equations this is assuming m_A=m_B=m and m_C=0The Attempt at a Solution p_4^2+p_2^2=2m^2c^2 but I'm not sure...

Here's what I have so far: (B_{ij} B_{kl} + B_{il}B_{kj})A_{ik}\\ =B_{ij} B_{1l}A_{i1}+B_{ij}B_{2l}A_{i2}+B_{il} B_{1l}A_{i1}+B_{il}B_{2j}A_{i2}\\ =B_{1j} B_{1l}A_{11}+B_{2j} B_{1l}A_{21}+B_{1j}B_{2l}A_{12}+B_{2j}B_{2l}A_{22}+B_{1l} B_{1l}A_{11}+B_{2l}...

Homework Statement If A_{ij} is a skew-symmetric tensor, and B_{ij} is a second-order tensor, evaluate the expression (B_{ij} B_{kl} + B_{il}B_{kj})A_{ik} and express the final answer in its simplest form. Homework Equations For a skew-symmetric tensor, A_{ik}=-A_{ki} The...

Amazing water trick?? Is this physically possible?? This vid has became viral recently. So is this physically possible?! I am skeptical from the way the water behaves when it washes away from the cup's shape. And the fact that the rest of the guy's uploaded videos are of animation stuff...

In the derivation of the relativistic kinetic energy, K=\int_{x_1}^{x_2}F\,dx = \int_{0}^{v}\frac{d}{dt}(mv)\,dx = \int_{0}^{v}(mv\,dv+v^2\,dm) here, my lecturer told us without showing that mv\,dv+v^2\,dm = c^2\,dm Can someone please give me hints on how to combine these two integrals? I...

Homework Statement Hello. I am doing some problems on integration by parts and got stuck on the following problems. Any help would be appreciated. i. \int \arcsin x dx ii. \int_{0}^{1} x \ln (9+x^2) dx iii. \int x^2 \arctan x\, dx Homework Equations u\,du=uv-v\,du The Attempt at a...

woops. XD the block rotating... Thank you very much for your help!

so the block is linearly accelerating to the right with respect to the table but still rotating counter clockwise?

After much thinking, I realized that i should have considered the forces acting on each body separately. Calling f the frictional force, we have acting on the block, F-f=M_b a_b...(1) Here Mb and ab are masses and acceleration of the block. f here is the frictional force acted by the can ON...

so it's accelerating at a=F/m?

huh, so the can is actually accelerating with respect to the table?

Homework Statement During a hurricane, winds can whip horizontally at speeds of 150 km/h. Given that the density of air is 1.20 kg/m3 and the wind after striking the person is brought to rest, calculate the force of the wind on the person. You may assume the person's area to be 1.50 m high...

Oh, that is a typo.. the 2 should have been the total area of the circle, \pi R^2. To simplify the equation, you must realize that dr^2 is so small that it could effectively be taken aa 0.

Assuming them as point masses would only yield approximate answers. Especially when we are dealing with a disk, and not a spherical mass. We could imagine that if R is big, then the sphere would be affected by the gravity exerted by the mass on the edges of the disk. Therefore, we can't...