Tagged Questions
1
vote
0answers
53 views
Calculate how hot PLA will become
I am trying to attach the shaft of a brass heating tip to a PLA component. My problem is that the tip will have to reach a temperature of about 200°C and the PLA can only handle a temperature of about ...
22
votes
6answers
2k views
How do whisky stones keep your drink cold?
From a discussion in the DMZ (security stack exchange's chat room - a place where food and drink are important topics) we began to question the difference between how ice and whisky stones work to ...
5
votes
3answers
226 views
How can I determine the coefficient $k$ in $ \dfrac{dT}{dt} = -k(T - 100 \mathrm{^\circ C}) $?
I recently spend some time on cooking and I'm curious about the time evolution of the temperature of the water. I did some experiment and the temperature is of the form
$$ T = 100 \mathrm{^\circ C} + ...
8
votes
3answers
528 views
How hot is the water in the pot?
Question: How hot is the water in the pot? More precisely speaking, how can I get a temperature of the water as a function of time a priori?
Background & My attempt: Recently I started spend ...
-1
votes
1answer
84 views
Funny classroom experiments [closed]
I'd like to perform some weekly classroom experiments to keep my students interested and curious about everyday physics. Those experiments have to be quite easy to set up and not too easy to ...
8
votes
4answers
757 views
What happens when you heat vodka in a microwave?
Since ethanol has a lower dielectric constant than water would the water heat up and boil before the ethanol? Would the water transfer heat to the ethanol and, since ethanol has a lower boiling point, ...
3
votes
0answers
76 views
Thermal imaging camera [closed]
I'm making a tea bag experiment (Make a hollow cylindrical tube from light paper e.g. from an empty tea bag. When the top end of the cylinder is lit, it takes off.) I need to know how hot air is ...
1
vote
1answer
257 views
Liquid with freezing point above 0 Celsius that could be use at ice rinks
Please help me with an answer to my dilemma:
Is there a liquid that could be used to fill an ice rink (non-explosive, non-poisonous, etc), and have the freezing point above 0 Celsius?
21
votes
1answer
693 views
Energy in bolognese reduction - lid on or off?
Generally, to let my bolognese thicken, I leave the lid off in order to "let water vapor escape." I am however distracted from enjoying the taste because I'm having doubts that my physical reasoning ...
2
votes
2answers
207 views
Demonstrate magnets adhere to conservation of energy pursuant to the laws of thermodynamics
I am looking for a way to demonstrate that magnets adhere to the laws of thermodynamics, in particular the requirement that energy in a closed system be conserved.
To adhere to the requirement that ...
3
votes
3answers
160 views
What are some creative illustrations of the nature of dissipative forces?
I'm teaching a conceptual introduction to physics for American 13-15 year old students this summer.
One of the main ideas I want to hit on is the relationship between energy conservation, ...
1
vote
1answer
319 views
Heat absorbed by a room
How can one calculate the amount of heat absorbed inside a room in a single day using the temperature readings of the day?
If the temperature has to be reduced from 30C to 20C how much heat should be ...
4
votes
3answers
1k views
Why does hot oil explode when pouring water on it?
I am puzzled to know, What is the reason of hot oil make sound and explode when we pouring water on it?
161
votes
19answers
55k views
Cooling a cup of coffee with help of a spoon
During the breakfast with my colleagues, a question popped into my head:
What is the fastest method to cool a cup of coffee, if your only available instrument is a spoon?
A qualitative answer would ...
13
votes
3answers
1k views
Home experiment to estimate Avogadro's number?
How to get an approximation of Avogadro or Boltzmann constant through experimental means accessible by an hobbyist ?
6
votes
3answers
3k views
Why do lightbulbs continue to glow after the light is turned off?
I've noticed that whenever I turn the lamp off in my room at night, the lightbulb seems to continue to glow for a minute or so after that. It's not bright though; the only way I even notice it is if ...
