Hard Definition and 1000 Threads

I am hot but I need fire, I am tall but I need to jump, I am long but I need to stretch and I am slimy but I need slime, I am full but I need fuel. I end in X. What am I?

Evaluate and express as a fraction in lowest terms -3 to the power of 4 + (-3)to the power of 3 - (-3)to the power of 2. (I apoligize...I don't know how to type powers on the computer...>_<) I tried to evaluate it like it told me to...so I ended up with 81-27+9 =63 Yet when I...

A pump, submerged at the bottom of a well that is 35 m deep, is used to pump water uphill to a house that is 50 m above the top of the well. The density of water is 1000 kg/cm^3. All pressures are gauge pressures. Neglect the effect of friction, viscosity. A) REsidents of the house use .35...

Well the top keys on my TI are really hard to press, I obviously spilled something but do not remember. Is there a way to make them easy to press again? It's getting really annoying :-[

I am trying to write a position vector for point D I originally thought that the z component was 0...but now common sense is telling me that it can't be...the rope must be sagging. Are my first to components correct or am I visualizing this incorrectly? : 8i+7j-(something)k <---or...

A baseball has a mass of about 0.14 kg, and it is pitched towards home plate at a speed of about 46 m/s. If the bat exerts an average force of 8900 N for 2.1 ms, what is the final speed of the ball in m/s?

A block of mass m = 0.900 kg is fastened to an unstrained horizontal spring whose spring constant is k = 94.5 N/m. The block is given a displacement of +0.120 m, where the + sign indicates that the displacement is along the +x axis, and then released from rest. (a) What is the force (magnitude...

Homework Statement 14. Figure 28-36 shows a metallic block, with its faces parallel to coordinate axes. The block is in a uniform magnetic field of magnitude {0.020{\textcolor[rgb]{1.00,1.00,1.00}{.}}T}. One edge length of the block is 25{\textcolor[rgb]{1.00,1.00,1.00}{.}}cm; the block is...

Hard Wave Question (Really need help pleasez!) The Bay of Fundy, Nova Scotia, has the highest tides in the world. Assume that in midocean and at the mouth of the bay, the Moon’s gravity gradient and the Earth’s rotation make the water surface oscillate with an amplitude of a few entimeters and...

Homework Statement An oscillator with a mass of 420 g and a period of 1.00 s has an amplitude that decreases by 1.20% during each complete oscillation. If the initial amplitude is 8.20 cm, what will be the amplitude after 50.0 oscillations? If the initial amplitude is 8.20 , what will be...

hi, there is a challenging problem that no one could answer it,so here it is if anyone wants to try: if x,z,y are all positive real numbers prove that: (1+x^2)(1+y^2)(1+z^2)/(xyz)>=8 so anyone can help please? thank you.

Q1 A kangaroo was seen to jump to a vertical height of 2.8m. for how long was it in the air? Attempt on the solution not possible? what do you guys think? Q2 A ball was photographed stroboscopically as it was released and fell freely. eight images appear on the phto which is...

Im having trouble installing a new HD into my computer. Where can I found information, accurate and up to date, about: partitioning, formating, fdisk, MBR, , multiboot, ... thanks.

hard trig question :( Homework Statement A,B, and C are three vertices of a cube, as shown in the diagra,. Find the measure of <ACB, to the nearest tenth of a degree. this is the diagram of the cube http://img144.imageshack.us/img144/6396/dsdsddry9.jpg with no given side and angle how...

MiH had a cameo in my dream last night. A guy who lived next door to a place I was visiting was experimenting with the aerodynamics of antenna probes, firing them off his balcony to see which would travel farthest and stick in the ground best. All these spiky things were protruding from his...

Hard gravitational force problem! Homework Statement [/b] Derive an expression for the gravitational force between a sphere with mass m and another sphere with mass M and radius R, IF the sphere of mass M has a spherical hollow inside which touches the surface of the sphere and the center of...

HARD problem on mathematical model and Fourier series Hi, I have this problem about creating a mathematical model. the context is Fourier series/transform. It is about finding a mathematical model for hourly temperatures . I have attached the file. I tried to search for Fourier model for...

Initially, a 2.00kg mass is whirling at the end of a string in a circular path of .750 m on a horizontal frictionless surface with a tangential speed of 5 m/s. The string has been slowly winding around a vertical rod, and a few seconds later the length of the string has shortened to .250 m...

I'm almost 25 years old and I've finally started going to college, for a bachelors in mechanical engineering. I feel like it's the perfect major for me: I love math and physics, and I love creating things. My only problem is that I'm not wild about the idea of having a 9-5 job, working 5 days...

Homework Statement Find d^2y/dx^2 in terms of x and y. x^2y^2-2x=3 Homework Equations property rule, chain rule, quotient rule, The Attempt at a Solution I can do this the long way, but there must be a shorter solution. Can I simplify it? I've found dy/dx=(-xy^2 +2x)/(2x^2y)...

Homework Statement How hard do you need to push a 2kg box which has .2 coefficient of kinetic friction so that it moves with a constant speed of 5m/s? [The Attempt at a Solution (I'm calling g 10m/s2 not 9.8) F(kinetic friction)=(.2)Fn=(.2)mg=(.2)(20N)=4N so...since the acceleration is...

Homework Statement The problem is to find an function that describes the tempurate variation with time and position of an infinitely long heated rod that is made by fusing together two semi infinite rods at x=0. They have perfect thermal contact but are made of two different materials and...

ok so this is my first post and I am not sure if what I am looking for is even possiable or that I am even posting in the right form.. anyways im looking for a way to find the specific heat of a water sample depending on the hardness, i measure hardness with grains per gallon (gpg). and I am...

A Hard differential equation! Solve: dy/dx = (x^2) + y

Let's say you're running a Fortran program that writes to the hard drive. What happens when the hard drive is completely full? Do other files get written over?

Find all triples of primes (p,q,r), that pq+qr+rp and p^3+q^3+r^3−2pqr are divisible by p+q+r. I really don't know how to start, (of course I've been trying)

Homework Statement Un a sequence 0 < x < pi/2 U0 = 2cosx Un+1 = quroot( 2 + Un) 1) Calculate U1, U2, and U3 in function of x (simplify maximum) 2) Show that Un = 2cos( x / 2^n)Homework Equations The Attempt at a Solution 1) U1 = sqroot( 2 + 2cosx) = sqroot( 2 (1 + cosx)) = ?? (now , how...

calculus(dv/(g-kv^2)) I think it's incalculable. Could anyone approximate it ?

Another hard physics problem?? Homework Statement A spaceship ferrying workers to Moon Base I takes a straight line path from the Earth to the moon, a distance of 384000 km. Suppose it accelerates at an acceleration 19.4 m/s2 for the first time interval 14.4 min of the trip, then travels at...

Homework Statement Calculate the maximum packing fraction of the unit cell volume that can be filled by hard spheres in the Hexagonal structure Relevant eq: Volume of spheres is number of lattice points multiplied with the maximum volume of one sphere. The Attempt at a Solution I...

a really hard one here. would appreciate help on how to do this question: a physical system is governed by the following: curl E = -\frac{\partial B}{\partial t}, div B = 0, curl B = J + \frac{\partial E}{\partial t}, div E = \rho where t = time, and time derivatives commute with \nabla...

Homework Statement http://img238.imageshack.us/img238/3648/hrwfop7echpt2128br6.jpg Homework Equations Coulomb's Law Vector Form: \vec{F}_{12} = \frac{k_{e}q_{1}q_{2}}{{r_{12}}^2}\hat{r}_{21} Scalar Form: \vec{F}_{12} = \frac{k_{e}|q_{1}||q_{2}|}{{r_{12}}^2}...

Homework Statement f is a continues function in [a,b] and has a second derivative in (a,b). L(x) is a line that goes through (a,f(a)) and (b,f(b)). Prove that if f''(x)>0 in (a,b) then L(x)>f(x) for every x in (a,b) Homework Equations MVT The Attempt at a Solution First of...

how can an elementary particle like a photon be massless? How can physicist measure and detect a photon if the don't know its inherent properties? I know a photon travels at the speed of light , but wouldn't you have to know a particle mass , in order to know its speed? Or are physicists...

Momentum Conservation --- so hard! Homework Statement Two automobiles collide at an intersection. One car of mass 1.4 X 10^3 kg is traveling at 45km/h [S]; the other car of mass 1.3 X 10^3 kg is traveling at 39km/h [E]. If the cars have a completely inelastic collision, what is their velocity...

i just can't figure this out. given a n x n matrix (with n>1) "A" such that all entries are integers and A is invertible such that A^{-1} also has integer entries. Let B be another matrix with integer coefficients so that: A+B, A+2B, A+3B, ... A+(n^2)B Are all invertible with integer...

So I use "date modified" as a sort of organizational tool - and would like to keep that. When my NTFS hard drive transfers files to a FAT32 hard drive, date modified attribute of folders is kept. However, I reformatted the FAT32 hard drive into another NTFS hard drive - and the date modified for...

Some diabetic patient's nails become really hard, and then they it's really difficult to cut them. Is there any thing by which your nails can become soft, and easy to cut? Is there any useful pedicure equipment? Thanks in advance!

isnt possible to make cost efficient spacecraft by putting multiple types of rockets on a ship which can then alternate rocket engine at different levels of the atmosphere and eventually escape into space?

hey here is my questions: Find all y satisfying the inequality z<y^2-6/y-1 problem is i do not know where to being, considering there is 2 unknowns. And the top doesn't break down which could simplify the question. Could someone help me out or help me start this question off? thank you.

can someone give me some really hard intergrals to solve? make sure they are in the range of calculus 1-2 (anything before multivariable) My teacher assigned some few hard integrals, and they are fun. I want to try moer. thanks.

Does anyone have a strong hard drive preference? I used to buy only Seagate drives, but I recently had a Seagate drive die and I'm thinking about going with another company this time. What do you guys think about Western Digital or Maxtor?

well atleast i think this problem involves integration. i also duno how to derive this into a formula. ok, so this rocket is taken out to space so there are no external forces acting on it (ie if the rocket moves at 2m/s it will continue to move at that speed FOREVER as there is no other...

My mum told me this one, it's pretty cool :). The red car and the blue car are having a race. The red car, which has a top speed of 70mph has a 20 minute head start over the blue car, which has a top speed of 80mph. Assuming that top speeds are reached the very instant a car starts, and...

Why do some people like sleeping on hard mattresses and others prefer softer ones? And why do humans need matresses and beds at all?

Hello, I just got my midterm back and kind of very disappointed. I am a Grade 12 student taking programming in C++. I am using the C++ for you++ book, which is kind of dry and doesn't explain alot. I took a course in C last year. I was very good at it. Was the top of my rather small class...

Hi all, I'm quite new to posting; just been reading around the forums when I came upon this question for my assignment. I'm really quite stuck and no idea how to relate the different values (such as number of moles of Barium Sulfate) found back to the unknown compound. An unknown compound...

1. If d|ab and gcd(a,b)=1, prove that d=d1d2 where d1|a and d2|b and gcd(d1,d2) = 1 Homework Equations 3. Let d1 = gcd(d,a). Thats all I know

"Simple" part of a hard problem involving momentum/kinetic energy conservation Two balls, of masses mA = 36 g and mB = 64 g are suspended as shown in Figure 7-44. The lighter ball is pulled away to a 60° angle with the vertical and released. (a) What is the velocity of the lighter ball before...

Homework Statement 1 oz of 80% pure (NH4)2SO4, 1 gallon of water @ 25 degrees Celsius. 1 gallon = 3.785 L, 1 oz = 28.4 grams. Suppose an avid gardener prepares a solution by putting 1 oz of 80% pure Ammonium Sulfate in a gallon of water at 25 degrees C. a) what is concentration of...