School of Physics

" I am looking for a physics student to meet with and discuss about this paper. " One of the earliest (perhaps the first) paper indicating quantum coherence involvement in photosynthetic systems was published by a team including researchers from UNSW Physics: https://www.ncbi.nlm.nih.gov/p...

As far as I know, the "electron cloud" doesn't have a well-defined meaning. It is often used as a metaphor for the wave function.
Often, the wave function is independent of time.

Yes, the Bohr model is wrong, so it should only be taught as an example of a historical dead-end. The 'cloud' is a metaphor describing the wave function. The electron state changes with the emission or absorption of a photon so, in that 'cloud' metaphor, the electron cloud has a different shape befo...

The video you linked has fairly detailed explanations. The problem is set up by collisions in classical physics, but it quickly becomes a couple of interesting problems in maths. For insight into the physics, see the Momentum chapter on Physclips http://www.animations.physics.unsw.edu.au/mechanics/c...

The link about centre of percussion is good This concept is applied to objects (like bats) that rotate before collisions. The TV show link in principle involves a rotating lever and a collision, but the shock in the man's hand is probably not the prime consideration, so we needn't consider the centr...

Why does photocurrent plateau with voltage in photoelectric effect? Good question. As voltage increases, the electric potential energy of the ejected electron will increase. Thus by the time it reaches the anode its velocity will be dependent on voltage. Correct. Ie more will reach the anode per un...

Can a transformer be considered ideal if we don't assume the wires to have no resistance? No. Further, even if the wires are superconducting, there are usually very significant losses due to hysteresis in the core—see the earlier discussion on that. Can the formula 'Power in = Power out' be used if...

A fault may be a short circuit, which has a low reactance and may draw a dangerously large current.

What if define any mass by Inertia, not how it does now Inertia by mass? In other words, change a general method to model systems. Just thoughts.

For many people, inertia and mass are synonymous. To avoid potential ambiguities, I usually avoid the term 'inertia'.

Moment of Inertia is not applied in Linear motion at all, if I don't mistake. If it is so, why isn't Moment of Inertia applied in Linear motion? It is not included in the linear motion of a particle , because particles have no extent, and so cannot rotate. If a macroscopic object is travelling in a...

If your definition of a particle is something that can be seen with the eye or photographed with an ordinary camera, then yes, an electron is not such a thing. In physics, particles have well defined position, moment and trajectory. Waves have well defined wavelength and frequency. I think that all ...

A direct measurement would be a very difficult experiment, because the gravitational effect is so small and any stray electric or magnetic effects so large. However, lots of indirect experiments have been made to look at possible different gravitational effects on n, p and e. Suppose that you measur...

If there are no charges present, then yes, an electric field can propagate at the speed of light. But your pieces of wire have charge in them. To change the voltage of a piece of wire, you need to transfer charge to its surface. The inverse ratio of those is the capacitance (C = Q/V). To transmit th...

The single wire has a (very small) capacitance per unit length. (In other words, you need to put a tiny static charge on it to raise its voltage. That tiny charge ends up on its surface.) It also has a (very small) inductance per unit length. (In other words, when you change the current, you change ...

There's a subtle point here. Before you close that switch, the left hand wire is at 10V, the RH wire at 0 V. A ms after you close it, the LH wire is at 10 V (bottom) and 5 V (top), varying smoothly between the two. The RH wire is at 0 V (bottom) to 5 V (top). (There is also a current flowing through...