jhobbie
• Member for 7 years, 7 months
• Last seen more than 7 years ago
• New York, United States

It stays the same, because it's dependent on the square of velocity. You're probably wondering where the extra energy goes because potential energy is falling. The answer is: it is dissipated into ...

The density of Dark Energy is not very high. In a place with lots of matter, the attractive forces of gravity are greater than the repulsive forces of dark energy. In mostly matter empty space, the ...

Temperature is a measure of the average kinetic energy of particles, characterized by a Maxwell-Boltzmann distribution. Basically, that's a fancy way to say, if something is at 25°C, a large ...

Your new constant would probably be $k/c^2.$ $k$ is actually a simplified expression for $1/(4 \pi \varepsilon)$ which is the permittivity of free space. For magnetic fields, you use the permeability ...

Note the vector signs! The vector signs mean that direction is included in the equation. So g only has a y component, but u may have components in any direction.

How sure are you that electricity travels at the speed of light? Although electricity propagation moves at the speed of an E/M wave, and not electrons, its speed depends on the dielectric constant of ...

Depends on the size of the circles, but usually angle of incidence = angle of reflection (in this case to a line tangent to the circle at point of incidence).

Yes. There's an even easier notation for dispersion, or standard deviation which is $$D(Q) = \sqrt{ \langle Q^2\rangle - \langle Q\rangle^2 }$$ Both those terms are the same. So $D(Q)$ is zero.

Often times, an operation is something that changes the state of the system, like a measurement. But it can be other things that will change the state of the system.

A simple explanation of Fermat's Principle is that you can approximate the path of the light by using the path that would take the least amount of time. For example if light is passing through only ...

The problem with centripetal acceleration is that it is not a vector, and cannot possible have a negative sign. It should remain "constant" in this case, but its direction is changing. But actually, ...

Wavelength doesn't change because of distance. However, because of Hubble's Law (Hubble's relation might be more accurate) the change does have a correlation with distance. It might help you if you ...

Well, assuming a lot of things aren't true, then no. For example, if the Earth was shaped like a pizza, and the sun revolved around it, then it would have the same transition.

You compare the size of the constants in the force law. For example $$F_g = \frac{GMm}{r^2},$$ and $$F_E = \frac{kQq}{r^2}.$$ In SI units $k= 9 x 10^9$, while $G = 6.67 x 10^{-11}$. That means to ...

To the first question: Newton's third law states that every force has an equal and opposite force. Thus, the force that Earth exerts on you with gravity (a big mass causing a huge acceleration on a ...

They don't fuse because you haven't put in the energy to bond them together. Joining any two atoms takes energy, not just holding them in the same spot.

Well... you don't really measure electric/magnetic forces at distances much larger than several meters, but that's because electric potentials are difficult to build up. I guess on the small end, it's ...

Are you aware that centripetal force is the net force on an object towards the center, and not a "real physical" force? It's simply an expression of other, more physical forces, such as tension, ...

I guess this is the same question as "If you have two bar magnets and were able to somehow fuse the two south ends together, would you then have a magnetic monopole" or something. Magnetism on a ...

Well, at that point it's pretty small, right? And I guess maybe you could take into account gravity from all other "nearby" sources (i.e. the moon and maybe other planets). In fact, the most notable ...