Mr X

I did an experiment where I had to measure the temperature of a vessel using thermocouples.

With the basic circuit, I got an EMF value of -0.04 mV. I then added an extension cable to see what effect it had and I got an EMF value of -0.08 mV.

If length is proportional to resistance which is proportional to voltage, shouldn't the voltage have increased with the addition of the extension cable? Are my results wrong or is this explained somehow?

A few weeks ago I fell on my wrist and it was bruised and generally quite painful for several days during which I couldn't do much with that hand.

Now, there isn't any pain if I squeeze hard on my wrist, if I pull with that hand or if I push something whilst keeping the wrist straight.

However, if I push something with my hand at a 90 degree angle to my forearm (eg. pushing something with an open palm (like the way you would do a press up)) then there is a pain in my wrist and I am unable to apply much force.

Does anyone know what the problem may be?

I am dropping steel ball bearings down a tube filled with glycerol.

The balls have the same density but different diameters and masses. Which ball will reach terminal velocity first, the smallest ball or the largest ball?

I have a large cylindrical tube that is filled with glycerol.

The tube is inclined at an angle to the horizontal.

I place a ball in it and record how long it takes for the ball to roll down the side and cover a distance between two markings.

Does anyone know of a formula I can use/test/prove for this?

I am assuming terminal velocity and can work out the viscosity/density.

I have a large cylindrical tube that is filled with glycerol.

The tube is inclined at an angle to the horizontal.

I place a ball in it and record how long it takes for the ball to roll down the side and cover a distance between two markings.

Does anyone know of a formula I can use/test/prove for this?

I am assuming terminal velocity and can work out the viscosity/density.

I need to buy a replacement battery for my laptop and I have the choice of 5200, 8800 or 10400 mAh capacity. Obviously the larger capacity batteries are more expensive so I was just wondering how significant the difference would be between the three.

Why is it that the uncertainty of an analogue scale is +/- half the smallest increment but the uncertainty of a digital scale is +/- the smallest increment?

I am doing an investigation where I have to measure the resistivity of a wire:

I used the formula P=R(A/l)

I measured resistance by measuring voltage and current then doing V/I

I measured length using a ruler

I measured the cross sectional area by using a micrometer to find the diameter then doing Pi x r^2

I need to talk about alternative methods that I could have used. I have talked about how I could have just measured resistance with an ohmmeter instead of measuring voltage and current but I can't think of much else.

What are other methods of measuring either resistance, length, or the cross sectional area? (or an entirely different method of finding resistance) They can be better methods or worse methods.

I have 5 different values for resistance, each with a different uncertainty:

8.62 +/- 0.162%

8.59 +/- 0.196%

8.62 +/- 0.248%

8.64 +/- 0.320%

8.63 +/- 0.463%

I worked out the average resistance by doing sum/5 but how would I work out the uncertainty on the average?

What sort of voltage/current would be required for a wire (constantan, approx 0.3mm diameter, 40cm long) to be heated to 250 degrees Celsius?

If there is a formula for this could you write it down.

I need to do an experiment to find the resistivity of a wire. My plan was to:

Connect the wire to a circuit and find resistance:

-would it be better to measure V and I then do R=V/I or to just measure resistance with a multimeter?

-what's the best way to connect the wire to the circuit? I could only think of crocodile clips but I hear that this isn't very effective....

I would also measure the length (several readings) and make a table with the different lengths and their respective resistances.

Then I planned on making a resistance vs length graph, finding the gradient and then multiplying it by the cross sectional area to get resistivity. (I will find the area by measuring the diameter of the wire with a micrometer)

I am going to repeat the experiment with another piece of wire made from the same material but with a different thickness.

Can anyone think of any ways to improve the experiment?

I am getting a new phone and 3 are offering the best tariffs by far. I was just wondering if there is a catch like bad coverage or something?

I would like to go into a career in finance (accountant, actuary, financial adviser e.t.c) and i wasn't sure which a-levels to pick. I was thinking of:

Maths

Further maths

Physics

History

They have good breadth and whatnot, but i wasn't sure if i should take business studies instead. My school doesn't do economics and i should get an A* at GCSE but i hear Business Studies isn't a very recognised qualification. Should I just stick with what i had in mind, or do you have any other suggestions?

Also, could you recommended some university courses for a career in finance.

Thank you in advance.

Yesterday i went down the beach, and after i while i started getting these strange shivers. It was like when someone "walks over your grave". It was a nice day and i wasn't cold so i wasnt sure why it was happening. Today i have been getting them again. This morning i was laying in bed with two duvets on and i was getting strange shivers again. it can't be because i am cold, so why is this happening?

I want to get a headset for my ps3 and i'm not sure which to get. would appreciate some advice from people with experience of either product, or just general knowledge.

(both are roughly the same price.)

I want to get a headset for my ps3 and i'm not sure which to get. would appreciate some advice from people with experience of either product, or just general knowledge.

(both are roughly the same price.)

i want to buy a mic for my ps3. could you recommend a good mic that doesnt cost much. i dont really wanna spend over £50.

i am looking for someone to play zombies with on ps3. (black ops)

you dont have to be amazing, i just want some people who:

-dont steal kills

-open doors when they have the most money

-dont die on round 3

just basic common sense really. you dont have to have a mic, mine recently broke anyway.

if you are interested, either add me or leave your psn

psn: nathan741

title says it all. depth please

title says it all, in depth answers please and with a hierarchy