Tagged: heat

Thermal expansion - Physics Stop

Marcus Wilson Jul 24, 2011

In the last couple of weeks I've been fascinated by the amount of thermal expansion demonstrated by the chimney flue in our new house. Like many New Zealand houses, there is a log-burner located in the living area. The flue basically consists of a vertical column of large (steel?) cylinders slotted into each other, going from the burner straight upwards … Read More

Hot air rises - Physics Stop

Marcus Wilson Jul 14, 2011

Well, we have now moved into our new house. We moved last Friday, mostly dodging the heavy showers that have been marauding around the country for the last week. We are slowly unpacking - the place is looking a lot tidier now than it did at the weekend, but it will take a while to find a home for every … Read More

Electricity and heat - Physics Stop

Marcus Wilson Jul 06, 2011

There's an advert that's well-featured on the television at the moment for a plug-in wall-mounted heater.  As part of the advert, the product is described as 'efficient'.  Now, I'm not at all saying that these heaters aren't a good purchase, but a bit of physics tells me that this statement about efficiency doesn't really mean very much - all heaters that … Read More

Wet house, dry house? - Physics Stop

Marcus Wilson May 27, 2011

We're looking for a new house at the moment.  We've decided to be a lot more environmentally friendly and shift out of Cambridge and move to Hamilton to cut down the pesky commute in the mornings and evenings. We haven't made much progress, though, with finding a house - what we're looking for is in short supply in the areas … Read More

Paint - Physics Stop

Marcus Wilson May 13, 2011

Question: What's more tedious than watching paint dry? Answer: Waiting for a dry day so you can put the paint on in the first place.Or, to be closer to the truth, waiting for a dry day so that the guy you've hired to do the painting can get on and finish it.  Getting the outside of a house in Waikato … Read More

Chocolate problems - Physics Stop

Marcus Wilson Apr 26, 2011

Thinking back to last week's MasterChef (the chocolate tower of terror - re-live it here), there were a couple of nice examples of cooking being a branch of physics. I've heard it said that cookery is all about managing the flow of heat into (or, in this case, out of) an object, which, of course, requires some physics.The … Read More

Uses of Liquid Nitrogen - Physics Stop

Marcus Wilson Feb 17, 2011

I went to the doctor yesterday and he attacked me with liquid nitrogen.  To be more specific, I had a wart 'frozen' off.  Now, I had some similar treatment years ago, in which the doctor used a container of the stuff surrounded by polystyrene foam, and open to the air. Rather like what we use in the lab sometimes. He … Read More

“It’s a rain forest, expect rain…” - Physics Stop

Marcus Wilson Jan 10, 2011

So says an information board at the Aniwaniwa Visitor Centre at Waikaremoana in Te Urewera National Park.  We know this well, so before heading down that way with the tent this weekend, we carefully checked the weather forecast.  "Mostly fine, with occasional showers", it advised, and the nice weather charts indicated a high pressure area settling over the … Read More

Hot, heat, temperature and thermodynamics confusion - Physics Stop

Marcus Wilson Dec 16, 2010

Consider the following perfectly reasonable sentences:"It's hot outside""The oven is heating up""Insulation helps keep a house warm"Here we have physics words and concepts being used in everyday English in ways that are rather loose from a physics point of view. Does the conventional English use of words such as 'heat', 'temperature', 'insulate', etc confuse students when they come to learn thermodynamics? For … Read More

Negative Resistance - Physics Stop

Marcus Wilson Nov 16, 2010

I was having a conversation last week with a student about negative resistances (in an electronics context). These are just as they sound - to send a current from terminal A to terminal B you have to apply a higher potential to terminal B than terminal A.  Sounds backwards?  Yes - it is. That's why the resistance is negative.It's not … Read More