For high Rise Buildings,say above 30 floors,wind energy could be too ample to be wasted.
So what kind of study has to be carried out in order to know the feasibility of installing Wind turbine above a building?
What will determine the power output of this turbine?
If we assume 70% of braked energy from the previous case is transferred to heat into two front brake rotors.How much would the mean temperature of front rotor increase when the vehicle is put to stop.
Assume that :
1)rotor's diameter is 3mm.
2)rotor's thickness is 1cm.
3)Density : 7800...
Supposing you had a cylindrical closed tank inside the body of a submarine; the top of the tank is at 200m depth. The tank has height 2.5m and internal volume 1.8m^3.
A section of pipework is connected between the top surface of the submersible (level with the top of the tank) and to the...
Hi guys,
Heard an interview question from a friend, the guy asked him what happens to a disk with internal radius r and external R such as the following:
When heated.
He told me the answer is that the internal radius gets smaller and the external gets bigger.
Can anyone help me understand why...
When we think about first world nations and world leaders in politics, ethics, economics, and science, we think of Western nations that are built on democracy, human rights, and freedom. But now we are facing a new situation where the prospective new world leader will spread its influence while...
Yes, yes I did my homework - I googled this and got many results but none seem to answer my query.
I am not a historian so bear with me.
I had a picture in my mind that civilizations seem to appear after we discovered agriculture and thereafter each civilization advanced and continued to...
In optimising the PID controller produced on Simulink, my controller has a step voltage of 100V and I am not sure if the rise time is the point where the response curve first reaches (or crosses)this point, or if it is the point where it hits the first overshoot peak?
Homework Statement
The question is such :
System is modeled as : y''+2y'+4y=u(t)
find the time at which the system goes up 75,90,95 % of its final value.Homework Equations
The Attempt at a Solution
I have no idea how to touch that,I tried to find the source of the regular rise time (from 10...
So for a class I am designing a solar dehydrator and I want to know how fast the hot air will rise out of the dehydrator. For calculation purposes assume the hot air is 120°F @ 30% relative humidity (23 g/m3) and rising through a tube (if necessary assume the tube is 4 in. in diameter), the...
Homework Statement
"A body of mass m, moving with velocity v, collides with a body of mass 2m at rest, in a head-on collision. The coefficient of restitution is 1/3. If the 2m body has a specific heat c, and if it is assumed that the two bodies share the heat generated in the collision equally...
1 - how does water rise to form clouds if oxygen is heavier than nitrogen?
when it turns into a gas its hydrogen and oxygen---why does it rise (to form clouds) if oxygen is heavier than nitrogen, which makes up 78% of the Earth's atmosphere?
*please note that I'm not confused as to the...
The DAMA experiment is again asserting detection of dark matter in the galactic halo. An earlier similar claim by the DAMA group was hotly contested several years ago. The new release, DAMA/LIBRA results and perspectives - http://arxiv.org/abs/1301.6243, resurrects the same claim of annual...
Homework Statement
At the Earth's surface, a projectile is launched straight up at a speed of 9.6 km/s. To what height will it rise? Ignore air resistance and the rotation of the Earth.
Homework Equations
Conservation of mechanical energy K_i + U_i = K_f + U_f
The Attempt at a...
Homework Statement
Consider a black box which is approximately a 10-cm cube with two binding posts. Each of these terminals is connected by a wire to some external circuits. Otherwise, the box is well insulated from everything. A current of approximately 1 amp flows through the circuit element...
Consider a ball tethered to a post by a string. The faster it spins, the higher it gets until the bAll is the same height as the place that the string is attached to the post. What force accounts for this?
Assume that I have capillary of radius 0.08 cm.
I want to test this capillary for capillary rise action.
Formula will be
T=hrgρ/2cosθ
what will be the rise for water.. ( please tell me the calculated value)
And, what will be the fall in mercury. ( How to show it negative as its...
The Helium balloon of total mass=0.200kg and volume 1.00M^3 is attached a a rope with mass density of 1.00g/m. How high will the balloon rise?
I know that air density is 1.204kg/m^3 and that the balloon will stop rising after the density on the inside equals the density on the outside.
I...
Homework Statement
Thermal energy is transferred to a solid. Three properties of the solid are:
1. volume
2. mass
3. specific heat capacitiy
Which of the above properties determine the rise in temperature of the solid?
A) 1 and 2
B) 2 and 3
C) 2 only
D) 3 only
Homework Equations
c = Q/mΔT...
Hi, and thanks for your expert opinions in advance. I'm working on a theoretical scenario of a flue gas funnel. Assuming hot air is rising from a funnel at a constant rate. Would the hot air rise faster if water droplets were sprayed at the top of the funnel, hence lowering the air temperature...
Motorcycle horizontal acceleration--front wheel rise
The distance between the centers of the wheels of a motorcycle is 171 cm. The center of mass of the motorcycle, including the rider, is 95.0 cm above the ground and halfway between the wheels. Assume the mass of each wheel is small compared...
hello all.there is a electric hoist cradle(Temporary personnel lifting;make fixator) which one of our contractor uses to clean the outside glasses of a high rise building.the cables are suspended up at the top railing with fasteners and then the electric motor escalates the cradle for use.the...
Homework Statement
Part 1: I have a cylinder of radius R and lengh L. At first i can assume that we have expansion in both R and L. And that i can use the linear thermal expansion coefficient(\alpha) = 4 \times 10^{-6}. The relative change in R and L is 1 \times 10^{-4}, and from that i have...
As the title states, can anyone help me understand what the difference between the two is? I've been trying to look everywhere but nothing really explains why they're different. I just thought it would be the same.
This is based on the capillary rise method for surface tension.
Homework Statement
At take off, the rotor blades of a helicopter propel 2400 kg of air vertically downwards each second. The air, intially at rest, is given a speed of 11ms^-1
QN: the mass of the helicopter is 2500 kg. Find the acceleration of the helicopter as it starts to rise...
http://en.wikipedia.org/wiki/Surface_Tension
Could someone help me solve the capillary rise method equation, with a worked example:
y= hpgr/2
Thank you soo much
Hello, I am currently working on a pulsed laser deposition (PLD) system whose volume is approximately 115 to 120 liters. As you can assume, there are a lot of ports in the chamber but a lot of them are windows or blanks (2.75, 4.5 and 6 inch). Significant ports (possible sources of leaks...
Will they rise slow and gradual allowing for a somewhat seamless transition of population to higher ground, or will there one day be a large storm that will inundate an area permanently?
What are the implications for the gulf coast, South Florida, and the East Coast?
How will vital...
"Information field" giving rise to quantum mechanics.
Hello. I stumbled upon a video on youtube where quantum entanglement is discussed (). A woman quotes Einstein: "There is no place in this new kind of physics for the field and matter, for the field is the only reality." What did Einstein...
We all think that by increasing the temp of a liquid, the surface tension would reduce and so capillary rise will not be as high. But on increasing the temp, the liquid's density also decreases and so the weight of liquid to be lifted also reduces. Which will have the dominating effect, decrease...
What is the relationship between continental drift/sea-floor spreading and global sea-level rise?
Kind regards.
Lucas Olsson
University of Gothenburg
Earth Sciences
lucas@student.gu.se
Homework Statement
I need to find a system rise time (from 10% to 90%) using matlab.
Is this code right?
The Attempt at a Solution
sys = tf(num, den);
y= step(sys, t);
tr1 = max(find(y<0.1));
tr2 = min(find(y>0.9));
rise_time = t(tr2) - t(tr2);
Is this seems to be right?
Hello,
I'd like to get some more accurate idea of entropy in general: dS=\int\frac{dQ}{T}
Given an adiabatic isolated system. Work is irrerversible done onto this system.
Entropy will rise because of the fact that some of the work is transformed into irreversible losses and therefore...
Hi, I did a pressure rise test on a chamber, where I closed the isolation valve and measured the increase in pressure over 30 seconds.
I want to use this information to calcualte the rate of accumulation of vapour in the chamber. What I'm looking for is the sublimation rate during freeze...
If a small tube (capillary tube) is dipped into the water, the water level rises. Which means someone is doing work on the water to rise it against gravity. My question is, who is doing this work?
My guess is the internal energy of the molecules is doing the work. That also means that...
Does the water approach the maximum height in a capillary tube with 0 velocity?I mean to say that does it go to the maximum height and just stop or perform simple harmonic motion ?Water is in equilibrium but velocity need not be 0 or is it(why?).The expression we derive for h should be for...
I can understand how can inflation give rise to the isotropy of the CMB, but that it can give rise also to the irregularities in the CMB...!?
Please, can anyone explain me this?
thanks.
Homework Statement
Blimps are being considered for use as freight carriers. A scale model rises when filled with helium to a volume of 55.0 dm3. When 1.10 mol He is added to the blimp, the volume is 26.2 dm3. How many more grams of He must be added to make it rise? Assume constant T and P...
Hi all. I'm looking for a paper that I've seen referenced in a couple of articles I've been reading. The paper is
O. M. Kiselev, Determination of gas-bubble shape in axisymmetric flow of fluid, Zh. Prikl. Mekhan. Tekh. Fiz., No. 3 (1963).
The English name of the journal is Journal of...
hi, if you had a litre container full of water with negligible air and nothing else and heated it at a linear rate from 50 degrees centigrade upto 200 degrees centigrade does the steam pressure rise linearly or exponentially?
the measurements are plucked from the air, its the rate of steam...
http://www.telegraph.co.uk/comment/columnists/christopherbooker/5067351/Rise-of-sea-levels-is-the-greatest-lie-ever-told.html
But if there is one scientist who knows more about sea levels than anyone else in the world it is the Swedish geologist and physicist Nils-Axel Mörner, formerly...
Hello,
Recently I have learned that magnetism causes the Lorentz force. The electric force makes sense to me in terms of virtual photons. But how do virtual photons give rise to magnetism and the Lorentz force. Is it because when the charged particle moves through an magnetic field it comes...
ok this was a problem in my book and the answer apparently is 29N.
I have the diagram and pictures below. I know that the pivot point will be the edge of the block that is touching the outside of the wheel. When the wheel is in equilibrium the sum of the torque will=zero so i can set up the...
Homework Statement
As a mechanical design project, we have to design a device that will lift a 1kg weight off the ground as high as possible when the only source of energy provided is 1.35L of 80psi compressed air. (it has to stay there so a slingshot/cannon is out of the equation) We are...
I am not smart enough to know the answer to this question. My son is being accused of touching a bike yes touching on the seat a bike on a bike rack which the school is claiming made both tires pop. The only way i see this as possible is if the bike owner aired the tires up in the morning around...
Homework Statement
A ball is thrown straight up. If its initial velocity is 24m/s, how high does it rise before it begins falling down?
Homework Equations
The Attempt at a Solution
This one is very frustrating to me. My teacher doesn't teach us, he just gives us the homework and...
Hello everyone.
I'm working on a video-game that takes place on a distant Earth like planet. A key part of the gameplay revolves around a special day and night cycle. I'd like this planet to be tidally locked to it's red dwarf star making it's habitable zone limited to the terminator.
Of...
My 21' above ground pool in northeast Ohio freezes each winter. There is 52" of water in it now and that is 3" below the wall caps. I usually don't have it this full, but we've had a LOT of rain lately. I was told to drain some water out of it so that the rising ice will not destroy the top...
In the past, Bohmians are a minority and more of a curiosity or side show and even now although it's getting more popular. But thinking it over and over. The alternatives are quite stranger. In Copenhagen for example. Do you actually believe that the interferences don't actually occur physically...