pressure

Dot Physics

Category archives for pressure

I am still thinking about the Red Bull Stratos Jump. Sorry, but there is just tons of great physics here. Next question – how big of a balloon would you need to get up to 120,000 feet? I am not going into the buoyancy details of Archimedes Principle – I think that was covered fairly…

Pressure demo: suction

How does a suction cup work? It is all about the atmosphere. Here is a demo. Take some type of “suction cup” device. In this case, I used a toy dart. Stick it to something smooth and lift it up. Like this: What lifts up the metal block? The atmosphere. Diagram time: But this isn’t…

Why do your ears hurt underwater?

This is a topic that I am going to talk about in my physical science class. Might as well make a post about it, right? Here is the deal. You are in a pool. You drop a quarter in the deep end and swim down to get it. I know the first thing you are…

Vacuum Spider-Man

Check out this thing. That is where the guy (Jem Stansfield of BBC’s Bang Goes the Theory) shows how he built this thing. Here is part 2 where he uses it to climb a building. Here are some questions: Why does it not matter how powerful the vacuum is? How does a vacuum cleaner work…

On a previous episode of The MythBusters, Adam and Jamie made a lead balloon float. I was impressed. Anyway, I decided to give a more detailed explanation on how this happens. Using the thickness of foil they had, what is the smallest balloon that would float? If the one they created were filled all the…

RP 4: More on the movie Up! (or Upper)

So, analysis of the movie Up is pretty popular in the blogosphere. Figure I might as well surf the popularity wave. So, I have a couple more questions. The most important thing to estimate is the mass of the house. I am going to completely ignore the buoyancy of the house. I figure this will…

Energy in an exploding water heater

The more I think about the last MythBusters’ exploding water heater, the more cool things I see. How about I look at the energy of the explosion. There are three things I can look at: How much energy went into the water heater from the electric source? How much kinetic energy did the water heater…

I haven’t seen the Pixar Movie “Up” yet, so don’t spoil it for me. I have, however, seen the trailer. In my usual fashion, I have to find something to complain about. There is this scene where the old man releases balloons out of the house. What is wrong with this scene? Also, would that…

Physics of the Water Rocket

I said I would come back to this, and I am. I am a man of my word. Yesterday, I posted a link to a video of this really cool water rocket thingy. How does this work? What is the physics going on here? I think this can be best explained with the momentum principle.

Word Police: Use of the word pressure

I know I should just let go, but this is what makes me, me. I understand that there are terms in physics (like for instance ‘pressure’) that are used in all sorts of ways in common language. The problem is when someone tries to explain something scientifically and misuses a word. Pressure means something. It…