Physics - October 2007

Assume that a truck, initially traveling at 45 mph, loses its braking as it travels down a 5% grade (5 feet down for every 100 feet of horizontal travel). Ignoring friction, calculate the maximum speed possible after the trunk has moved 2 miles down the slope after the clutch went out.

How do I set this up? Thanks.

2007-10-13 06:14:28 · 1 answers · asked by labelapark 6

2007-10-13 06:10:57 · 1 answers · asked by Anonymous

I don't understand cuz when radiation collides with atoms, it can knock electrons out of their srtucture, creating a charged particle!!so that means the charged particle has to be positive cuz the atom has lost it's electron and left with more protons!!but in the book it says the ion can be negative!!but i don't understand why??

2007-10-13 05:48:26 · 10 answers · asked by Anonymous

I need help with how to do with problem. If someone can show me the steps. I really don't get this.

An object is launched at an angle of 20 degrees with a speed of 30 m/s. It hits 4.0m up the face of a wall. How far away is the wall? (Note: Use Quadratic formula to find time.)

2007-10-13 04:59:44 · 2 answers · asked by neverisenough 1

INFORMATION IS CHANGE FROM ONE FORM TO ANOTHER FORM BUT IT IS NOT DISTROIED CAN WE APPLY ENERGY CONVERSATION THEOREM TO IT.

2007-10-13 04:53:05 · 3 answers · asked by Anonymous

2007-10-13 03:31:09 · 4 answers · asked by Anonymous

The Inadequacies of Science


I feel compelled to show the inadequacies of science, I will render it into a belief system as well.
I take this position because all of science is inductive. Conversely, if you think of a deductive argument you’ll see that the argument is valid because the conclusions are contained implicitly in the premises. Such as the argument;

Premise 1: Socrates is a man,
Premise 2: All men are mortal,
Conclusion: Therefore, Socrates is mortal.

Validity is assured because there is not anything in the conclusion that is not already contained in the premises. But when one considers scientific (inductive) arguments, such as an argument to prove our premise that “all men are mortal”, it seems we do not have this type of validity. For in the case of inductive arguments we go from evidence to hypothesis as opposed to going from premise to conclusion. This means that there is more information in the hypothesis than what the evidence can warrant, whereas, in deductive arguments the information in the conclusion is less than or equal to that of the premises. Therefore, the evidence of mortality of a few individuals misleadingly establishes or supports the hypothesis that all men are mortal. Another example may be for one to say that all Hispanics speak Spanish. For that to be true that someone will have to witness every Hispanic that has lived, does live and will live to verify that statement. Yet, many believe that all Hispanics speak Spanish on the basis of the millions that do speak Spanish. However, I do not speak Spanish. Similarly the mortality of men is assumed in this same way. However, there could be someone out there right now who was born 2,000 years ago and has not yet died. Or the next baby born in Japan may never die.
Of course it could be argued that scientists do not proceed from evidence to hypothesis in an arbitrary manner. They “of course, can justify the move from observation (which is the evidence) on the basis of rules, so as to form the hypothesis by generalizing the observations made. Therefore, the move from evidence to hypothesis is justified on the basis of some kind of principle rules, say the scientific method. However, what are the justifications for using these rules?
The rules that are used are justified by assuming a uniformity of nature. This uniformity of nature can be stated in multiple ways. Unobserved instances will resemble observed ones. The future will resemble the past. Every event has a cause and like causes yield like effects. Thus the uniformity of nature is guaranteed by assuming the principle of causality and causation as depicted by David Hume (where Hume claims that causality and causation are not provable, and are not analytic truths, but are instead synthetic empirical truths of which cannot be verified empirically because these principles of causality and causation is what it is meant by a uniformity of nature).
Now here’s the crucial point. There is no ground for the belief in the uniformity of nature, because any such belief would have to be grounded in induction, of which in turn is grounded in the uniformity of nature. Thus any attempt to ground the belief that there is a uniformity of nature is circular. Supposing that there is no uniformity of nature, then I doubt that there even can be rules to use any way.
However, there are some that will say that science is not necessarily inductive. For example, Karl Popper rejected induction when developing his methodology of science. Popper argued that as long as such hypotheses are falsifiable, in the sense that there are possible observations that would disprove them, then the objectivity of science is assured. However, Popper’s falsificationism offers no account of our entitlement to believe in the truth of scientific theories, rather, they only warrant us to believe in their falsity, and so fail to solve the problem of induction. Popper himself stated that it is impossible to verify or even to confirm a universal scientific theory with any positive degree of probability. What we can do though is to disprove a universal theory. That is why we do not believe in the truth of a scientific theory, but their falsity instead. Is it true that scientists always reject their theories when faced with counter-evidence, as Popper says they should? And if the most we can ever do in science is to disprove theories, how do we know which theories to believe and act on? Popper says that we ought to act on those theories that survive severe testing, yet testing involves observing nature of which is the problem in question. Therefore, he fails to solve the problem of induction, thus induction remains the problem.
Another response to the problem of induction is offered by Bayesian confirmation theory. Bayesians argue that our beliefs come in degrees, and that such degrees of belief, when “rational, conform to the probability calculus”. They then argue that Baye’s theorem implies a rational strategy for updating our degrees of belief in response to new evidence. SADLY, in relation to the problem of induction, this strategy implies that our degree of belief in a scientific theory should be increased by observations which are probable, given the theory, but probable nonetheless because it is based on induction. It also leaves one asking when updating these degrees of belief, to what are they conforming to? They say they are getting closer and closer to the truth, but how do they know that they are getting closer to the truth when the truth is not known? So what are they getting closer to?
I also want to wager that most scientist and people for that matter are not familiar with the concept of idealism. Philosophical idealism is not the same as an attitude to be observed in life. It is rather a metaphysical theory about nature of reality and thus presupposes a distinction between appearance and reality, drawn in an other than common sense way. In general, it maintains that what is real is in someway confined to or at least related to the contents of our own minds (of which in turn is loaded with assumptions). What are the reasons; therefore, for thinking that reality is confined to the contents of our minds/ideas? It is because where the perceptions of qualities of things, such as color, taste, warmth, light, is circumstance dependent (i.e. relative to the context in which perception takes place, e.g. the illumination for the eyes) those qualities cannot be real properties of things. It is argued that this is applied to all perception. Since perception is a matter of having sensations or ideas, and since to be is to be perceived, only sensations or ideas can properly be said to be or to be real. The theory of perception, therefore, remains a part of the apparatus of empiricist thought, and is implied in David Hume’s doctrine.
Immanuel Kant held, however, that a mere subjective, idealism would not do in that it did not make it possible to distinguish properly what is objective from what is subjective. Kant thought that idealism must be transcendental, which he tried to define by saying that appearances are to be regarded as being on and all, representations only, not things in themselves, and that time and space are therefore only sensible forms of our intuition, not determinations given as existing by themselves, nor conditions of objects viewed as things in themselves (Critique of Pure Reason).
At any rate, all these forms of idealism have in common the view that there is no access to reality apart from what the mind provides us with, and further that the mind can provide and reveal to us ONLY its own contents (implying that the contents of the mind may or may not represent an external reality). Therefore, science must assume that an external reality exists, and that this reality actually corresponds to what the contents of our minds reveal to us.
Do you know what the funny thing is? It’s funny how science makes theories based on observations, and generalizes these observations to come to a universal theory, like all men die. So it seems that we should infer from pessimistic meta-induction that since all scientific theories have been wrong from Ptolemy to Steve Hawkins, that all current and future scientific theories are ‘probably’ going to be false too. Now I understand that there are those scientific buffs who understand that science is not the end all say all, but for those of you that keep ramming science down

2007-10-13 03:29:10 · 8 answers · asked by l_tone 2

2007-10-13 02:58:09 · 2 answers · asked by laura 2

2007-10-13 02:44:34 · 3 answers · asked by boomerrangg 2

how to find Vcc value for operational amplifier?

2007-10-13 02:14:38 · 1 answers · asked by Anonymous

A block is hung by a string from the inside roof of a van. When the van goes straight ahead at a speed of 29 m/s, the block hangs vertically down. But when the van maintains this same speed around an unbanked curve (radius = 170 m), the block swings toward the outside of the curve. Then the string makes an angle with the vertical. Find .
=___ °

2007-10-13 02:00:47 · 3 answers · asked by Santina E 1

and everyone knows that when there's a nuclear explosion, zombies come out!

2007-10-13 01:38:05 · 5 answers · asked by sonofgreatbigfeet 1

.......creating this new temporally venced sequence resulting in this alternative reality

What should we do?

2007-10-13 00:38:21 · 6 answers · asked by Anonymous

2007-10-13 00:21:47 · 6 answers · asked by blagomira95 1

Have a go at the following and let me know if you worked it out...Concentration is needed here...Slighty lift your right foot off the ground while sitting down and rotate it clockwise. Now, rotate your hand anti clockwise at the same time, keeping your foot rotating clockwise at the same time... Got it?

2007-10-12 22:27:17 · 3 answers · asked by BFCP 3

1.because then what about heliospheric current sheet ,if it would have been perfectly vacuum then the sun's msgn filed strength would've been diminished at larger dist. bu its not quite sio on the other hand it increses???
2-if electric field doesn't modify space-time then how can it be effective in vacuum(where there is no other matter to transfer its "effect") and moreover it shows linkages to space in the fact that the elctric effect of a charge travel with c=3*10^8 m/s>>>>>>>????????????????/


plz give full explanation...
fast!!

2007-10-12 22:10:07 · 7 answers · asked by Swapnil B 2

Our rubbish is fudamentally made out of the same stuff as Uranium and Plutonium and according to E=MC^2 even something with of a mass of half a kg will still have 9x10^8j (900 000 000j).
So why arent we turning our rubbish to energy?

2007-10-12 20:40:37 · 6 answers · asked by futuretopgun101 5

A ball is thrown vertically upward with a speed v by a man standing on a cliff.
When the ball passes the man on the way down, assuming no air friction:

a) Its speed is equal to v.

b) Its speed is less than v.

c) Its speed is equal to 2v.

2007-10-12 20:24:10 · 4 answers · asked by Anonymous

Like thousands of caapcitors releasing charges like a timer over twelve hours from a single charge?

2007-10-12 20:21:32 · 3 answers · asked by joezen777 5

The period T of a particle in uniform circular motion is:
a)Does not depend on the speed.

b) Directly proportional to its speed.

c) Inversely proportional to its speed.

2007-10-12 20:19:43 · 1 answers · asked by Anonymous

2007-10-12 19:48:17 · 5 answers · asked by seph 2

2007-10-12 19:44:49 · 2 answers · asked by smart 1

2007-10-12 18:22:40 · 2 answers · asked by joezen777 5

A hand grenade is thrown at an angle of 35 degrees from the horizontal at a speed of 58 miles/hour. 1.6 seconds after it is launched, it blows up.

1. How high above the ground is it? (ft)
2. How far is it from the thrower?

My answers come out to:

1. 39 ft
2. 111.5 ft

I'm fairly certain about the second one, but I'm not sure about the first answer. Help?

Thanks.

2007-10-12 18:18:44 · 3 answers · asked by labelapark 6

i am making a circuit in which 26 LED's are connected in parallel. i am supplying current from 2 AA size (1.5 v) batteries. which resistor should i use to prolong the life of the LEDs?

2007-10-12 17:14:43 · 5 answers · asked by suhas m 2

A firecracker is tossed straight up into the air. It explodes into three pieces of equal mass just as it reaches the highest point. Two pieces move off at 120 m/s at right angles to each other. How fast is the third piece moving?

2007-10-12 16:58:33 · 1 answers · asked by Jerry M 1

A person is standing on a sheet of ice so slippery that friction may be ignored. This individual fires a gun parallel to the ground. When a standard cartridge is used , a 17-g bullet is shot forward with a speed of 270 m/s, and the person recoils with a speed of vc. When a blank cartridge is used , a mass of 0.2g is shot forward with a speed of 60 m/s , and the recoil speed is vb. Find the ratio vb/vc.

2007-10-12 16:50:50 · 2 answers · asked by Anonymous

For instance, in the physics lab we did with 2 carts colliding in elastic and inelastic collisions, the total change in momentum was not zero. What momentum are we not accounting for and why is the effect not noticeable?

2007-10-12 16:19:33 · 6 answers · asked by kp86 2

This is for a school project
matterial that are a must.....
Small/Large bag
May use anything else but, not premade coolers, extra ice...

2007-10-12 15:38:01 · 6 answers · asked by cc C 1

I really love physics, but all we're learning right now are vectors and d-t, a-t and v-t graphs. So i stayed after class and asked my teacher about blackholes, long story short he said if you're going at the speed of light you can see aroung the corner before you get there... i've been thinking about that for quite some time but i just don't understand what he meens.

2007-10-12 14:33:04 · 7 answers · asked by stefany 1