The stupid questions thread.

[Lemontime]

But considering the lack of gravity, won't the push of the tool box not produce any force? In other words, him pushing his toolbox away will not make any difference, as the force he outputs upon the toolbox is not equal to or greater than his own mass?

Buggered if that makes any sense, been a while since I did any science..!

 

[g-fish]

As you say harry, been a while since you've done any science.<3.

How does a rocket turn in space?

By using thrusters in any given direction to slow/turn/speed up.

 

[Lemontime]

As you say harry, been a while since you've done any science.<3.

How does a rocket turn in space?

By using thrusters in any given direction to slow/turn/speed up.

And the thrusters exude a force greater than or equal to the ships mass / velocity. Therefore giving it the ability to slow/turn/speed up!

 

[adman]

Nah - the OP was correct. If you weigh 100kg, and you have a 10kg tool (say... Silly Wabbit) and you throw Silly Wabbit at 10 metres per second, you would move at exactly 1 metres per second in the opposite direction, since their is no external force acting upon you and there is no air resistance AND your mass is 10 x greater, so your velocity is about 10 x smaller.

You would continue to move at that same speed in the other direction until you catch your shuttle. If you found another tool such as Kembla Downhill (Jokes mate!) and threw him after Silly Wabbit, you'd move at 2 metres per second.

Just keep throwing away those tools until you find your ship.

Another useless piece of infomation from Adam!

 

[nomajneb]

But considering the lack of gravity, won't the push of the tool box not produce any force? In other words, him pushing his toolbox away will not make any difference, as the force he outputs upon the toolbox is not equal to or greater than his own mass?

Buggered if that makes any sense, been a while since I did any science..!

Okay, the hole in your understanding that I can see is that you're considering gravity to only exist either on or around Earth. Gravitation is defined as the force by which mass's are attracted to eachother, for example, if there was NO gravity in outer space then why does the Earth orbit around the sun?
My understanding is that nowhere in the universe will gravity be entirely non-existant and as such, the push from the toolbox will posses force proportional to the gravitational force. Or something along those lines.

I'm just clutching at straws with this next bit as honestly I don't know too much about all this, but if the gravitational force causes you to have such small mass then while your push off the spacecraft causes a greater than normal acceleration, then won't the toolbox will be similarly 'reduced' in mass and your throw be similarly increased and have a similarly greater acceleration?

Feel free to correct me if I'm wrong anywhere

 

[adman]

And the thrusters exude a force greater than or equal to the ships mass / velocity. Therefore giving it the ability to slow/turn/speed up!

Technically wrong. You can only accelerate. You can however accelerate in different directions, causing your velocity to change. Velocity is a vector, meaning that distance plays a part in its use. Speed is not a vector.

Something I only grappled recently in Physics is that if you run a 400m race on a standard track your velocity is...

0!

 

[Maurice.]

Nah - the OP was correct. If you weigh 100kg, and you have a 10kg tool (say... Silly Wabbit)

You.Win.Adam.

 

[g-fish]

I think a diagram is in order.

Nothing like MS paint to understand astronomical physics

 

[nomajneb]

Something I only grappled recently in Physics is that if you run a 400m race on a standard track your velocity is...

0!

I'm tired and not too sure of myself, but surely only your initial and final velocity would be 0. Given that vectors have both magnitude and direction, if you run say 100 of the 400m in say, 10 seconds, then your displacement in the x direction (at 0 degrees) is given by;
displacement = rcos(theta) where r is the magnitude and equal to, by the Pythagorean Law the square root of (x^2 + y^2)
Since you've moved 100 in the x direction and effectively 0 in the y direction, your magnitude is 100... and cos(0) = 1.
so your displacement is infact 100m from its original starting point in a direction of 0 degrees. This'll be used later.

From here, you have to go from acceleration and integrate
So, assuming your acceleration at any time has a magnitude of a (sure it's constant, deal with it.)
acceleration in the x direction = acos(0)
= a
since acceleration is dv/dt
velocity in x direction = at + C where c is the integration constant and effectively your initial velocity which is equal to 0, unless you get a running start.
v(x) = at.
Since velocity is given by dx/dt
x = 1/2at^2 + C where C is your initial displacement = 0
so, you rewrite this as
x = 1/2(v)t
100m = 1/2*v*t
1/2v = 100/t
v = 2*(100/10)
v = 20m/s at the 100m mark moving in a direction of 0 degrees from the initial point.

So there. by my reasoning at 10 at night your velocity is not always 0. Your overall SPEED however is infact 0 since the speed, or magnitude of the velocity is given by distance/time.. so you've effectively travelled 0m over a given time.. and therefore have a velocity of 0.

Once again feel free to say if i'm wrong.
I'm going to bed goodddnight farkin/rotorburn.

Edit: also I have no idea if what i've said is relevant to anything you were previously talking about, I just grabbed onto the your velocity being zero thing.

 

[Daneel]

I think a diagram is in order.

*SNIP*

Nothing like MS paint to understand astronomical physics

so yeah, if his toolbox weighed 10 kilos, he'd have to throw it at 100+ m/s to counter his existing momentum, 100m/s is crazy fast, no one in the world throws that fast. mind you, i wouldn't call 10m/s drifting either, more like flung off

a more realistic situation is something on the order of 0.5m/s drift speed, in which case he'd have to throw the toolbox (of mass 10kg) at over 5 m/s, a much more achievable speed - in this case, it would save his life safest way to do this is chest-pass style - trying an overhead throw would cause him to backflip over and over again and he'd still be moving away from the spaceship the force of the push has to be on your centre of gravity, which is around 2-3cm below your navel.

 

[Lemontime]

Well you're a dumbass for fixing your ship without a harness in the first place..!

End of story!

 

[Breaka]

Ok, right. I believe in evolution but I need a rough explanation of one thing.

I'll use Human's as an the example here. So, we evolved from Monkey's or Ape's if you will, howcome Apes and their various species still exist. Have they evolved from the same ancient type of Ape us Human's have evolved from but remained somewhat the same?

If that question doesn't make sense I'll re-phrase it.

cheers dudes!

 

[slip]

Lots of different species exist of the same thing in nature. Frogs, birds, fish etc. Paging Arete.

 

[thecat]

Ok, right. I believe in evolution but I need a rough explanation of one thing.

I'll use Human's as an the example here. So, we evolved from Monkey's or Ape's if you will, howcome Apes and their various species still exist. Have they evolved from the same ancient type of Ape us Human's have evolved from but remained somewhat the same?

If that question doesn't make sense I'll re-phrase it.

cheers dudes!

It's a bit like saying if mountain biking evolved from clunckers/cruisers how come clunckers/cruisers still exist.

Just because a branch grows from a tree doesn't mean the tree dies. Just because a second branch starts growing doesn't mean the first branch falls off

 

[g-fish]

No, I THINK that the theory of evolution states that the first branch does fall off. But 5 new braches grow in its place.

So humans evolved away from apes - becoming more intelligent, but so did apes, they evolved and became better climbers or honed specific skills.

So the apes of tens of thousands of years ago, aren't the same as the apes that live today.

Animals constantly evolve as their enviroment changes, but, if you look at an animal like a shark, it hasn't evolved in thousands of years, because it is the top of its food chain and doesn't need to. It's design is still perfect for where it lives.

 

[thecat]

No, I THINK that the theory of evolution states that the first branch does fall off.

Not exactly. Some twigs grow for a bit but lead to dead end

So humans evolved away from apes - becoming more intelligent, but so did apes, they evolved and became better climbers or honed specific skills.

in other words both branches are still growing, just in different directions

 

[g-fish]

in other words both branches are still growing, just in different directions

Yeah guess so, but the first branch doesn't stick around in it's orginal form. So it doesn't fall off, but it doesn't keep growing as it's own single entity

 

[Arete]

Most speciation is thought to occur in allopatry. This is a massively oversimplified explanation.

That is what was one population of the same species gets seperated from another, either by travelling across an ocean, a mountain range developing between them, etc.

As such the two populations no longer interbreed. The two populations are then exposed to a unique set of selection pressures - different food sources, different climates, different predators. As such, different physical features become desirable in the two different populations, and combined with stochastic genetic drift, you wind up with two different looking populations of animals. If the seperation and differing environments persist for long enough, you'll wind up with two populations that are different enough that they can no longer interbreed and produce successful offspring.

In humans - around 4 million years ago, equatorial rainforest underwent a severe contraction in geographic distribution. As such, some apes in Africa were forced to abandon the forests and live in the grasslands that the forests were turning into.

Being able to climb no longer had any advantage. The apes had to simultaneously look for food which was scarce compared to in the rainforest and avoid a suite of new, giant, effective predators. As such, being good at solving complex problems and standing on your back legs so you could see a long way were very advantageous, and developed independantly multiple times (the homo, cro and neantherthal lineages).

Humans were the most successful of these grassland ape lineages and the others went extinct. The apes that remained int he forests however, persisted and went on a different evolutionary path due to the different selection pressures that forests subjected them to.

 

[C0na]

Now what's worse? Biting into an apple and finding a worm or biting into an apple and finding half a worm?

Biting a worm then finding an apple..

 

[fairy1]

Can your body break down small bits of floating bone? I was supposed to go for an X-Ray on my hand as I had a bit of bone growing upwards behind a knuckle, long story short it snapped off and went somewhere. Will I die much??