Cumulative General Science/Technology Quiz

[ainwood]

Scales, whilst ostensibly measuring 'mass' do nothing of the sort - they measure net downward force. Anything that impacts the net downward force will affect the reading on the scales (using scales in a swimming pool, or in a wind updraft would massively impact it).

In this particular case, the water would indeed provide some buoyancy, and it would therefore be expected that it would affect the scales reading. However, this force would be applied as a torque force around the center of mass of the person, not as a direct force against the body. A torque force would be cause a reactionary force.

Net effect: I doubt it would affect the reading on the scales.

 

[brennan]

Mise gave the most precise answer, however I think Dutchfire's was good enough and he beat Mise to the punch.

Yes, I have actually done this little experiment btw.

You're up Dutchfire.

 

[dutchfire]

If you drop two identical magnets from the same height, one through a coil made of a conducting metal and one through normal air, which one will reach the ground first?

 

[SS-18 ICBM]

The one dropped through the air.

 

[brennan]

What Mr ICBM said. The magnet dropped through the conductor will lose a small portion of its Kinetic Energy as it induces a current in the conductor.

 

[Mise]

IIRC the magnet won't even touch the ground at all, instead oscillating between the top and bottom of the coil (ignoring air resistance). Maybe I'm thinking of something else though...

 

[SS-18 ICBM]

You need more energy to do that.

 

[brennan]

IIRC the magnet won't even touch the ground at all, instead oscillating between the top and bottom of the coil (ignoring air resistance). Maybe I'm thinking of something else though...

Nope.67890

 

[Mise]

Okay, well at least now I'm free to wiki what it was that I was thinking about when I said that...

 

[dutchfire]

The one dropped through the air.

Your turn

And brennan gave the explanation.

 

[SS-18 ICBM]

I'll pass it to brennan.

 

[brennan]

I thought of a good one earlier. but now i'm tired and can't remember it, so i'll take a raincheck on it if you don't mind. Someone else can have a go.

I'm strongly suppressing the urge to post a picture of an aeroplane on a treadmill...

 

[Brighteye]

Name me either an organ or (physiological) fluid in which you'd expect to find higher than normal concentrations of selenium.
Or even tell me what it does in the body.

 

[ori]

all sexes: thyroid, males: testicles
there are quite a few seleno-proteins though I have a hard time remembering them. It is essential for thyroxine to tri-iod-thyronine (spelling? - I only know the German name) metabolism, plays a role in spermiogenesis and I believe there are some anti-oxidant proteins that contain Se as well.
Never really got interested in so that is about what I remember from Med School...

 

[Brighteye]

Mostly in antioxidant proteins, but specifically in the thymus and testes (and semen). Your question.

 

[ori]

ok some genetics then:
for what physiological function do you need the members of the largest gene family (largest in vertebrates that is)?

 

[GoodGame]

"What is Immunology?" for a $100.

A.k.a. the immune system, the antibody specificity / epitope recognition, that white-yellow pus-sy stuff.

ok some genetics then:
for what physiological function do you need the members of the largest gene family (largest in vertebrates that is)?

 

[StarWorms]

I think I heard somewhere that the olfactory receptors were very diverse, but does that count as a gene family?

 

[ori]

"What is Immunology?" for a $100.

A.k.a. the immune system, the antibody specificity / epitope recognition, that white-yellow pus-sy stuff.

actually the epitope recognition is done by surprisingly few genes this is accomplished by recombination mechanisms and DNA editing...

I think I heard somewhere that the olfactory receptors were very diverse, but does that count as a gene family?

the olfactory (smell) receptors make up about 3% of all human genes (there are about 400 genes that are expressed plus about 600 pseudogenes in the human genome).
You are up

 

[StarWorms]

What are STRs (genetics)? Name two things that their identification can be useful for.