Recent content by Herman Trivilino

No. A theory is an attempt to describe the way Nature behaves. The words you use to describe that behavior have no effect on the theory itself. Why? It's just an argument about semantics. Words can be defined to mean anything you want. Definitions are always true.

You don't give a finite size to the electron. Last I checked the upper limit on the size was about ##10^{-18}## m.

The elevator in space is being accelerated by an external force. For example a rope is tied to the roof of the elevator and pulls on the elevator with a constant force. As long as the elevator is small enough there is no way to distinguish between being in the elevator in space and the elevator...

Spacetime is a geometric construct that is very useful to physicists in describing and predicting the way Nature behaves. The aether, described as an actual substance filling all of space, is of no use whatsoever in describing or predicting the way Nature behaves. It is of historical interest...

You mean the conservation laws give different results. Conservation of momentum is a purely dynamical relation. Conservation of energy isn't, it includes thermal interactions. You're getting a "different result" because you are ignoring the thermal interactions.

If you swap ##m_1## with ##m_2## in the expressions for the final velocities those expressions will be unchanged. Note the grammatical error in the textbook. They refer to the expression for the two final velocities. It should be the plural "expressions".

Ideally, the microphone should be very close to the opening in the pipe. Blow softly (don't "overblow") in an anechoic environment. I had somewhat similar issues with an acoustic guitar. Placing the microphone inside the guitar and lightly plucking the string solved things.

Language of course differs. But I have always seen the language used in the following way: For a closed pipe the first overtone, for example, is the third harmonic.

Whether you call it the Lorentz force or the magnetic force is just a naming convention. But the fact that it's perpendicular to the magnetic field is an observed behavior of Nature, it doesn't seem like a convention to me.

Who's in charge? Skills are something that they are taught, in this case by a teacher. Allowing them to do only what they "care" to do is not a good strategy. Vernier.com is a good resource.

Because in problems like this we assume the rod is rigid. That is, it won’t bend. Due to ##\vec{D}## or any other force.

It's an equilibrium situation so all the forces are "balanced" by other forces. That's what it means to have a net force of zero. Do you have any idea where your belief comes from? Learning involves examining your own cognitive processes.

Suppose you have the following three forces, all measured in the same units: ##7 \hat{i}, -4 \hat{i}, -3 \hat{i}##. They all lie along the same line, sum to zero, and are not equal but opposite.

Even in one dimension you can have three forces adding to zero. It wouldn't make sense to say that they are equal and opposite.

True. But the problem implies that it's a coordinate acceleration of ##6g## in this particular scenario that causes the blackout. So evidently blackout occurs when an accelerometer reads ##5g##.