well I just made up that graph. I can't show the data that I'm working with because it's confidential. Anyhow, there are graphs where if I apply the Chebycheff's Inequality, I get a negative value for the lower limit.
Homework Statement
This is not really a homework problem, but it looks like a rather easy problem that I can't quite figure out.
So I have a graph like shown in the attachment: a quantity vs time graph with some data points. I had no problem finding the average, but now I want to find...
Hey I need help with this proof:
Consider the cubic function: x^3 + bx^2 + cx + d = 0 . If the two solutions of the cubic function are not equal, ie r != s, but r=-s, then prove that bc=d.
Thanks
Would stainless steel be compatible with LOX, and what using brass for kerosene?
Is true that ball valves in general are bigger than solenoid valves because ball valves need an extra actuator?
I've looked at the Valcor cryogenic valves, and they either have a Cv that is too small or the...
Thanks for your replies
I'm building a LOX-Kerosene fueled rocket. I need some fuel that goes to the igniter for the first 10 seconds, and then the rest of the fuel goes to the main combustion chamber for 90seconds.
The flow rates and other properties are:
LOX: 1.5 L/s , -186 degree C ...
Hi,
I want to know the difference between an actuated ball valve and a solenoid valve. Which one is more reliable? I want to program the valve so that it allows flow for 10 seconds to one outlet and after that direct the flow to the second outlet. I know I'll probably need a 3-way valve...
Hi,
I need to find a suitable material for o-rings for my rocket. It will be used in the mounting of a stainless steel combustion chamber, so I need the o-ring to be able to withstand high temperature and pressure. Any suggestions?
Thanks
I decided I am going to use a spark plug, and I have the Go-Ped Kicker spark plug in mind. Has anyone else used it before?
http://www.msdpowersports.com/go-ped.html" [Broken]
Well to address everyone's concerns, this is an university student project team, and our goal is to build a reusable rocket capable of carrying a payload. We have obtained a permit from the Canadian rocketry association for launches. There are approximately 30 people working on this, and this...
Okay, so I'm building a liquid propulsion rocket, about 4m tall, with a 2000lb trust. The propellants used are liquid oxygen and kerosene. Now the trouble is to find a way to ignite the fuels to start the combustion. Do you guys have any ideas? Thanks!
Well I'm just not sure what happens when
\int_{0}^{1}dx/x^{1/3}
I think it converges, but I"m not too sure.
because when that function is below 1/x on the graph
The Hibbeler's book is awesome. There are so many examples in there, and a tons of problems. You can pretty much learn the whole course by just looking at the examples.
But with current technology and the current need for space exploration, do you think that it is necessary for NASA to be spending billion dollars of tax payer's money just to send a few people up there for no incredible productive reasons?
Pengwuino, I see your point. Going into space is indeed a big risk, and I'm sure most of the astronauts are willing to sacrifice themselves. But I still think that safety's first. I don't think there is much that humans can do that robots can't do. Like for repairs of satellite, the...
I'm writing a research paper for my english course, and I've decided to do my paper on whether or not we should replace all human space missions with unmanned missions. What are your opinions on this matter? And do you know where I can find some articles on this topic? Thanks
I know that airbags isn't the best option, because you never know where the rocket will land and they can only deflate once. Are there any options for protecting the rocket during landing other than airbags?
Hi, I'm building a rocket, and my team is planning to use airbags to protect the tanks from crushing during landing. I'm a newbie at this, and I want to know where I should start:)
Thanks
I'm doing this problem from Mastering Physics, and I'm really stuck on this problem
Assume that, when we walk, in addition to a fluctuating vertical force, we exert a periodic lateral force of amplitude 25 N at a frequency of about 1 Hz. Given that the mass of the bridge is about 2000 kg...
I want to know the formula to find the temperature of outer space by measuring the wavelenghts of the electromagnetic radiation coming from that area. Does anyone know what I'm talking about?
Thanks you for all the advices.
I think I'm going to try engineering the first year and see how I like it. If I don't, then I'm going to major in theoretical physics. If I don't try engineering, then I'll never know what it's like, especially since I've always thought I was going to be an...
I"m in grade 12 now, and I'll be going to university next year.
I got accepted to Engineering, but now I'm not sure if that's what I really want to do. I love theoretical physics, and I don't mind majoring in that, except I'm not sure what are some career options. I don't like lecturing...
Help, I'm trying to find the hypervolume of a hypersphere and I'm stuck on this:
V^4= 2(\frac{4\pi} {3}) \int_0^r (\sqrt{r^2-x^2}) ^3 dx
I don't know how to do the integration, and I can't expand the (\sqrt{r^2-x^2}) ^3
The answer should be \frac{\pi ^2}{2}r^4
Please help, thanks
Thanks xanthym for the good explanation,
however, I still have a question about the first question.
If the polar ices are melting, then wouldn't that cause the Earth to have a smaller "radius" (from the center of the Earth to the top of the polar ices)? Just like how a figure skater spins...
WIMPs are really hard to detect because first like the name tells us, their interactions with "normal matter" is weak. Also billions of those are passing through the Earth, and even our bodies every second, and yet they don't leave a trace.
Gravity can actually be repulsive. Gravity doesn't just depend on mass and distance, but it also depends on pressure. If the pressure is negative, then gravity then becomes repulsive, and that's basically what contributed to the early expansion of our universe according to the inflation...
Question #1:
If all of Earth's polar ice were suddenly to melt into the oceans, in the short term the length of the day would
a) increase b) remain the same c) decrease d)first decrease, then increase
The answer is a) , but why?
Question #2:
An ice cube of pure fresh water...
I'm already lost here, lol. How did you get 4*pi when you integrate 2*pi*sin(r)? Shouldn't it be 2*pi*(-cos r) if you take the antiderivative?
And what do you mean by "integrate between 0 and pi)?
Thanks
I'm building a hovercraft, and I am using an old computer fan to blow air into a plastic garbage bag and fill it up. I need to poke a few holes on the bottom of the garbage bag to let the air out, and I want to have a less friction as possible. What size should the holes be? And how many?