swansont

A parallelogram doesn't have a fixed angle, nor are all the angles necessarily the same, so it can't be the answer. The sum of the angles is 180. If the exterior is half the interior, then it's 60 exterior and 120 interior. Hexagon. Are you sure you copied the question correctly? If you reverse the relationship then you get 60 degrees for the interior angle, which would be an equilateral triangle.

And the goal is to help you work through it, not provide the answer, since you likely didn't learn a damn thing that way.

There is no outward force, and centipetal = "center-seeking" so a centripetal force will never push anything out. The electrostatic force is a centripetal force for a classical picture (i.e. Bohr model) but don't take that picture too far, since the Bohr model is not accurate in its portrayal of how an atom behaves. So you can equate kQq/r2 and mv2/r If the net force were zero, the electron would travel in a straight line, by Newton's second law. Gravity, being so small, can be ignored. An exercise for the interested: calculate the electrostatic and gravitational attraction of a proton to an electron at the Bohr radius (5.29 nm), which is the most-probable-radius for an electron in a Hydrogen atom.

Instead of sarcastically admonishing me for not answering a question you didn't ask' date=' you could have politely asked the question. Particle accelerators use electric fields/forces to accelerate particles. You turn them on and off so that the particle always feels a force that tends to speed it up. I believe most designs have basically a linear motor system. If you move a conductor through a magnetic field, you incude a voltage and try to drive a current. If you drive the current instead, you move the wire. This is how generators and motors work. The actual force is electrostatic.

And the part you're missing is...?

It's because water has its highest density at ~ 4 C, so that water sinks to the bottom, and the coldest water is at the top.

The quantum foam is related to zero-point energy. Nobody doing accelerator experiments is worried about it, because there's no known way to tap into it. It's an artifact of the QM solution to the harmonic oscillator, and basically there's a remainder that's infinitely large. You think of the universe as a large box, and solve the "particle in a box" for the EM vibrational modes. Each mode has an energy of (n+1/2)hbar*w, so even if there are no photons per mode, there's this (1/2)hbar*w of energy, for an infinite number of modes. But there's no known way to access it. You can decrease it, which gives the Casimir force, but energy is unsurprisingly conserved in that situation.

And I'm asking you to act just a little bit like a scientist and recognize that scientific theories aren't guesses, and not all hypotheses deserve equal consideration. The notion that, because of its inductive nature, all of science could be wrong, occupies essentially zero time in a working scientist's day. Why? Because things do fall down. And relativity does work. Any theory that might come along that's better won't tear down relativity, just like relativity didn't eliminate Newtonian gravity - we still use it for the cases where it's valid. There's nothing to be gained by stopping and declaring, "But all of this could be wrong" every five minutes.

Not that there's anything wrong with that.

Unless the state is actually forcing the president to use a clergyman, there's no conflict. The phrase often heard at the end, "so help me God," isn't in the Constitution. It's added, as desired, by the individual. The first amendment isn't there to keep religion or religious people out of government. It's to keep the government from forcing religion upon the people. There are plenty of places this is happening (creationism and so-called "intelligent design" teaching in a few schools, for example) that a lawsuit of this nature is just silly.

The kinetic energy does not stay the same, because the collision is completely inelastic. You have to use conservation of momentum during the collision.

The period depends on sqrt (l/g) So, as YT said, the distance to the bob, which can depend on environmental factors such as temperature, as well as the accceleration due to gravity. All else being equal, a pendulum swings more slowly on the top of a mountain, or even when the moon is overhead.

Onion skin, perhaps, or something similar.

He posted that 2 years ago, so I'd cut him a little slack.

If it keeps glowing after long periods without any light to charge it up, it's radioactive. That means the phosphor is being charged up by a decay.

I just got one, but reclicking on the link then worked OK.

Any glow-in-the-dark paint you can acquire these days is not likely to be radioactive.

How can something be "very unique?"

"This web site is intended as a time-of-day service only. It should not be used to measure frequency or time interval, nor should it be used to establish traceability to NIST or the USNO." "REAL time" is a bit of a misnomer. It all depends on how well you can realize the definition of the second, and transmit that information. Over the internet, that's limited to about a millisecond with NTP (Network Time Protocol) Anyway, the two sources in the US, as the site says, agree to better than a microsecond. But the USNO follows the BIPM (the International standard) a little more closely. But then, we contribute upwards of half of the data that they collect. edit to add: and I always chuckle at the mention of "the" atomic clock. The time that gets disseminated from USNO is the averaging of dozens of atomic clocks.