JustStuit

Four Seasons is amazing. I like pretty much all classical music though.

Elsa's Procession - Grainger

I joined this board over a year ago & it still says I have no post even though I have posted.

 

Sly

Posts in general discussions and some non-science forums don't count. There are many threads about this if you use the search function.

When [math]b[/math] is the ball and [math]c[/math] is the rigid car -

[math]m_bv_b+m_cv_c=m_bv_b'+m_cv_c'[/math]

=> [math]m_bv_b=-.3m_bv_b+m_cv_c'[/math]

=> [math]v_c' = \frac{1.3m_bv_b}{m_c}[/math]

As opposed to the squishy car -

[math]m_bv_b+m_cv_c=m_bv_b'+m_cv_c'[/math]

=> [math]m_bv_b=v'(m_b+m_c)[/math]

=> [math]v' = \frac{m_bv_b}{m_b+m_c}[/math]

If this is correct, then the the rigid car will have a larger velocity. It will not be exactly the number because of air resistence, heat, etc. but it should still be larger than the rubber/absorbant car.

The metal will still go further because the change in direction of the ball required a greater momentum change which also must be observed in the momentum (velocity in this case since mass is constant) change of the car. Momentum is conserved and a greater momentum change in one object requires the same amount of momentum change in the other (some will be transferred to air resistance but it will still be more than the rubber/springy car.)

I don't have my camera with me right now. Until then:

Hmm, you might want to have that blue nose checked out and wear clothes more often.

That is me.

...

There is enough information (assuming the cars are of equal mass) because the ball that bounces backward has a much greater change in momentum. Since momentum is conserved, the car will also have a greater change in momentum and since mass is constant this means the velocity increases.

The metal, solid car would go further because the ball had more momentum change. Because momentum is conserved, the car also must have a larger momentum change.

Your gentle aura entices my very soul and makes me think of sticky cheesecake. I bet you hear that a lot though.

I seem to have the opposite problem, none of my SNES cartridges work, I have to blow in them and hit them before they load. They also freeze up and lose saved data. Maybe the rough coaxing is not good for them.

Possibly on great apes or some monkeys but how do you propose a stone or plant get its IQ tested?

I would definitely recommend calculus and one science, what ever you're most interested in. My ACT science score rose 4 points since I came here (well it may not be related but it's nice.) I don't do as well in english but the math and science made up for it. On the science part you have to read about some experiments and comment on them and after reading through many it was pretty easy. Read each question carefully.

You haven't found evidense against god because it is not science and cannot be tested, proved, or disproved. This doesn't say its wrong/right just that it is religion and not science.

What would a government have to do with it? Or is this political? Governments aren't always right anyway.

I answer the ones I know . I know that is the equation for rotational inertia but it may be like newton's gravity and not work in some cases. I don't know if this is one of them. I think that is a pertinent question because being able to create such a senario would be an important part as the rest is null if it initially defies current law of physics.

Why? What about a pole that is 75 000 000 000 m long? You think that is impossible? A spacship spitting the pole out while making it as it moves in a strait line with negligable gravitational forces acting apon it should be able to do it.

No, making a pole that long that weighs the same amount as the 20m pole.

 

 

Q3)Would twisting or pushing this pole be harder than twisting or pushing a pole with the exact same mass' date=' higher density and a length of 20m, because of the limiting factor of the speed of the propogation of the force?

 

[/quote']

It would not be harder to twist because the formula for rotational inertia of a cylinder is [math] I = \frac{1}{2}MR^2 [/math]. The radius is the distance from the outer point of circle to the axis of rotation which stays the same in both cases and so does the mass. The problem would be creating a pole with a density low enough to be that long and still rigid and stable. It would be impossible.

Well, part of the carbon is left because the trees are still there, minus some leaves and bark usually. Most forests keeps growing and spreading anyways.

Highschool physics does it all the time with 100 percent efficiency scenarios.

Yes it is done but the answer is not exactly correct. It is done so that problems can be worked out and the answer still be very close without involving advanced techniques. Without doing this, phsyics 1 would be virtually all conceptual.

I'm not sure but, the CO2 from the fire comes from the CO2 the plants took from the air to convert to oxygen and carbon. Therefore, a forest burning forest could not put anymore carbon (in what ever molecule) than it took in while it was alive. For that matter it could not even put out as much since it leaves most of the trees. Plus, many plants grow back. So the fires aren't as harmful as never having the forest. Is this right?

I don't personally believe him because I don't have any trust in him. He may be right, but I don't have any reason to believe it.

I guess I'm just used to people with crappy spelling.

Like on IRC?