Gareth56

So why is a toaster cord shorter and thicker than a lamp cord?

So if there's nothing connected to the 240V output socket what is the current that is "waiting" to get used by some appliance? Is it 13amps, which I suppose is quite a lot of electrons available for use?

Gosh, i didn't know it took so little current to cause such damage. My 13amp electric kettle is pretty lethal then

What's lethal to a human then?

Presumably these items cannot deliver anything which would be considered dangerous or even lethal. I always thought it was the current that did the damage not the voltage. So presumably it doesn't take much current to fry a fly?

I've bought one of these electric fly zappers in the shape of a small tennis racquet, it runs off 2 AA batteries and virtually vapourizes small flies so what's the current of one of these things? I understand the voltage produced from the 2x1.5V batteries is 1500V. G56

As I thought. Yet another another error to be taken into account. Doesn't anyone proof read these books prior to publication! The Dummies Physics Workbook is even worse!!!

I'm going through the above book but sadly it's riddled with errors and typos. One possible error I'm slightly unsure about is as follows: 1/2(8m/s^2 , 33m/s^2)(1.0sec)^2 = (8m, 33m) Is this calculation correct? I don't think it is because the 1/2 hasn't been taken into account. Thanks Gareth

As I'm not an electric kettle or table lamp how do I end up getting an electric shock if I put my finger in the live outlet of my wall socket?

So a 2.5kW kettle sucks more electrons out of a wall socket compared to a 100W table light. I ask these questions because I'm just wondering how you get an electric shock. If I stick my finger in the live terminal of my wall socket I'll get a hell of a belt but is my finger sucking any electrons out of the socket?

So is it corerct to say that the higher the current of an appliance then the greater the amount of "suck" it has?

Thanks for the replies. Why is it ten if electrons are moving slowly that if I use fairly lightweight wire to connect a 2.5kW kettlethen the wire itself gets very warm if not hot and possible melts but if I use a thicker wire all remains cool? It's as if the kettle is sucking the electrons out of the wall socket at a terrific rate compared to say a 100W table light.

How fast are electrons moving when they leave the electric wall socket in your house (240V in the UK)?

I'm not sure if this question has been asked before, apologies if it has but where did the Supermassive Black Hole(SMBH) that resides at the centre of our (and other) Galaxy originate? I appreciate that "ordinary" black holes are the remnants of massive stars that have burnt out and collapsed but are SMBHs the same? If so then did the precursors of SMBHs exist before the formation of galaxies?

So in the above example the radius of that circle would have been 10deg and a diameter of 20deg?

Like this? See attached file. Radius.doc

But that method doesn't give you any sense of the magnitude of the radius of the circle. For example a circle with radius 20m is far larger than a circle with a radius of 20cm. I'm still not clear on how does a radius given in degrees denote the magnitude of the radius. As an example from the astronomy magazine I've just read. It's about Sun Haloes. It explains a haloe as being a "bright circle of apparent radius of 22deg." To me that description doesn't give any description of how large the haloe is.

I often read in books of the radius of a circle being expressed in units of degrees. What does this mean? I'm used to writing and measuring the radii of circles in units of length but not angular units. For example what does a circle of radius 22deg mean and how would you determine the radius of a circle in degrees? Thanks G56

Two nans at the most and they are only under the grill for no more than 2 minutes and certainly don't emerge burnt.

On two occassions now following grilling nan breads our carbon monoxide monitor has gone off in the kitchen. I've checked that it isn't the gas grill on it's own that's giving of CO becuase I've just lit it and left it on for several minutes. The alarm only goes off when it's grilling nan breads!! Any ideas?

I understand the inverting aspect but not why refracting telescopes reverse left and right as when I look at the srface of the Moon the dark maria appear on the left when looking through the scope but when I look with my eyes they are on the right hand side.

So we're still no wiser as to why a telescope reverses an image.

Looking through my telescope (refracting) I note that right & left are reversed, why does a telescope do this and not binoculars?

In a chemistry book I saw the following calculation with regard to entropy:- S = 1.38 x 10^-23J/K x ln2^10^22 (or if it helps 2superscript10superscript22 or 2 raised to 10 to the power of 22) The answer is apparently 0.096 J/K So how would you calculate ln2^10^22 using a calculator? Thanks G56

I agree, the human eye cannot detect all wavelengths otherwise we would see the sky as being more purple than blue and also wouldn't require night vision goggles to see objects at very low light levels! It's how the brain interprets the result of the interaction of the radiation with the molecules (via electronic transitions) within the cones located at the back of the eye.