Recent content by twang

Dale is correct ... and to add another detail, some tubes will glow various colors when they're in operation because they have quite a bit of gas inside. See here: http://thetubestore.com/blueglow.html That gas will *also* carry heat to the glass envelope of the tube.

That would vary from pendulum to pendulum... there's no way to calculate how long it keep swinging without knowing the sources of friction. There's friction 1. in the bearing of the pendulum's pivot point (unless its a wire tied to a point, in which case there's energy lost in the wire) 2...

Consider the huge surface area of a steel-wool pad. It will displace much less water than a steel sphere of equal volume. Water displacement is *not* related to surface area.

Heat travels in three ways: conduction, convection, and radiation. The heat from the hot, glowing filament is radiated outwards, just as the sun radiates infrared radiation, just as the heat from a bonfire reaches you hundreds of feet away. The current passing through the tube also heats...