Physics

### The Physics Philes, lesson 112: Sea Shell Resonance

I know last week I said that we’d look at how standing sound waves applied to musical instruments, but as I was preparing I realized that it doesn’t really illuminate anything, so I’m moving on resonance and sound. Sound good to you? Great. Remember that a normal mode is when …

Physics

### The Physics Philes, lesson 111: The Legend of Kundt’s Tube

So far in our discussion of waves, we’ve learned about nodes, antinodes, and standing waves. However, we’ve really only seen what these looks like with respect to transverse waves on a string. But sound waves are longitudinal waves. How do these concepts apply? As it turns out, much the same …

Physics

### The Physics Philes, lesson 110: Ring My Decibel

OK, friends. Let’s talk about wave intensity. Wave intensity (denoted with an I) is the average rate of time energy is transported per unit area across a surface that is perpendicular to the direction of propagation. So, if we’re talking about a transverse wave on a string, the wave might …

Physics

### The Physics Philes, lesson 105: Physics Makes Beautiful Music

Over these past several weeks, we’ve learned a lot about mechanical waves. However, what we’ve learned is a simple version of the waves we come in contact with every day. For example, the sound string instruments make are complex standing waves. To illustrate this, let’s think about what would happen …

### The Physics Philes, lesson 94: Sinusoidal Infection

Last week we started talking about mechanical waves. Now that we have some of the essential knowledge under our belts, let’s dig in a little deeper. It’s time to start talking about periodic waves. A note: Everything you’re about to read goes for both transverse and longitudinal waves. But it’s …

### The Physics Philes, lesson 93: Do the Wave

We’re chugging along in our journey through introductory physics. We’ve made it through a discussion of fluid mechanics. Now it’s time to start learning about mechanical waves. Before we dive in, we need to nail down the basics. A wave is a fairly familiar thing. Most of us have seen …

### The Physics Philes, lesson 92: Slow as Molasses

So far in our discussion of fluid mechanics, we’ve assumed that the fluid we’re talking about has no internal friction and has a laminar flow. However, there are important fluids that don’t follow this pattern. What about those? In that case we need know about viscosity and turbulence. First, let’s …

### The Physics Philes, lesson 91: Go with the Flow

Last week we learned about the continuity equation in fluid mechanics. To refresh your memory, that equation says that the speed of the fluid flow can change along the path of the fluid. The pressure can vary, as well, depending on the height of the fluid and the speed of …