Minimum Definition and 1000 Threads

Homework Statement A 1-kg steel rod is at 227C and is dropped into a 1-litre bath of water at 27C. Assume that these materials are thermally insulated from the rest of the universe. You will determine the final temperature of the steel rod after it reaches thermal equilibrium with the water...

Homework Statement A mass of 2.0 x 10^2 g is tied to a 1.6 m long string and spun in a vertical circle. What is the minimum frequency to keep the mass moving? Homework Equations Fc=m4(pie)rf^2 The Attempt at a Solution I know I have to use this equation and make it equal to another to find Fc...

Hello everyone, not sure if this is the right forum to post to, but I hope you can help me out. I am not a math person and am completely dumbfounded when it comes to engineering. I believe my request should be pretty straightforward for a person with the right knowledge. Basically, I'm thinking...

Hello Is the principle of minimum action applicable to nonholonomic systems? Why? If this question is already answered in this forum, just tell me, and I will delete this thread. Thank you for your time :) Greetings PS: My mother language is not English, so I'll be glad if you correct any...

Homework Statement A 65 kg airplane pilot pulls out of a dive by following at constant speed, the arc of a circle whose radius is 300 m. At the bottom of the circle her speed is 180 km/h. a.) Calculate net force on pilot at bottom or circle. b.) Calculate force exerted on pilot by seat at top...

1. Homework Statement A 3.0-kg block sits on top of a 5.0-kg block which is on a horizontal surface. The 5.0-kg block is pulled to the right with a force ##\vec{F}##. The coefficient of static friction between all surfaces is 0.63 and the kinetic coefficient is 0.38. What is the minimum value...

Homework Statement Find the minimum distance between the curves y^2 - xy - 2x^2 = 0 and y^2 = x - 2. Ans: 7/(4*root2) Homework EquationsThe Attempt at a Solution It's supposed to be done using concepts from parabolas. I tried using calc but it got convoluted.

Indicate whether you think it is a local maximum, local minimum, saddle point, or none of these? My solution: Point P = Local Max Point Q = Local Min Point R = None Point S = Saddle I got a 75% for first attempt, so one answer is not correct and I am not sure which one isn't.

If there is maximum speed in the universe and we call it c, and it is not relative, is there also some ultimate rest state, an unrelativistic "0" speed? I sort-of know that there is none, because it would mean that there exists a non-relativistic frame of reference. But I can't quite grasp what...

Homework Statement Find the absolute maximum and minimum values of f(x,y) = y^2+x^2 -4x + 11 on the set D where D is the closed triangular region with vertices (8,0),(0,4) , and (0,-4) . Homework EquationsThe Attempt at a Solution [/B] fx = 2x - 4 fy = 2y Critical point = (2,0) The...

Homework Statement Find the 4 critical points f(x,y) = 5ycos(9x) closest to (0,0) Homework EquationsThe Attempt at a Solution fx = -45ysin(9x) fy = 5cos(9x) fxx = -45*9ycos(9x) fyy = 0 fxy = -45sin(9x) y=0 x=pi/18 (0,pi/18) (0,pi/18 + pi/2) (0,pi/18 - pi/2) (0,pi/18 + 3pi/2) Was not...

Homework Statement -A beam of electrons bombards a sample of hydrogen in its ground state. a) Through what minimum potental difference must the electrons be accelerated if only one line of the Balmer's series can be observed? Homework Equations V= h^2/2meλ^2 (V=potential difference)...

Homework Statement [/B] The question "What is the minimum wattage rating the resistor should have?" comes after a previous problem I did to determine the maximum and minimum current when given a resistors tolerance. Here are all the values from that problem, some aren't really important but...

Minimum Distance between y^2=4x and x^2+y^2-12x+31=0. Attempt:I got that the parabola has vertex at(0,0) and focus at(1,0).The Circle is centred at (6,0)and its radius is sqrt 5.I figured that the double ordinate that passed through (6,0) would be bisected at the point.So I found out the chord...

Homework Statement the minimum distance for a car traveling at a speed of 30m/s is 60 m, including the distance traveled during the driver's reaction time of 0.44s. what is the minimum stopping distance for the same car traveling at the speed of 41m/s? v=30m/s, s=60m drivers' reaction time =...

Homework Statement Determine the minimum mean square error for the joint PMF. You will need to evaluate ##E_{X, Y}[(Y - 14/11\cdot X - 1/11)^2]##. Homework EquationsThe Attempt at a Solution The answer is ##\frac{3}{22}##, but when I work it out, I get ##\frac{203}{484}##. From my values, I...

Hi, Suppose you want to prove $|x - a||x + a| < \epsilon$ You know $|x - a| < (2|a| + 1)$ You need to prove $|x + a| < \frac{\epsilon}{2|a| + 1}$ So that $|x - a||x + a| < \epsilon$ Why does Michael Spivak do this: He says you have to prove --> $|x + a| < min(1, \frac{\epsilon}{2|a| +...

Homework Statement A hollow pipe has an inner diameter of 80 mm and an outer diameter of 100 mm. If its end is tightened using a torque wrench using 80 N forces, determine the maximum and minimum shear stress in the material. Where are they located? Note: In the diagram of the picture, the...

Find the minimum value of F(x)=\int_{x^2-2x}^{0} 1/(1+t^2)\,d Does it has a maximum value? why?

Homework Statement Consider a wedge of mass m whose upper surface is a quarter circle and is smooth. The lower part is rough. A small block of same mass is kept at the topmost position and the initial position is shown in figure. The block slides down the wedge. Find the minimum value of...

This is problem 1.16 from Kleppner & Kolenkow's Introduction to Mechanics. I didn't know whether to post it here or pre-university math. A sportscar, Fiasco I, can accelerate uniformly to $120$ mi/h in $30$ s. Its maximum braking rate cannot exceed $0.7g$. WHat is the minimum time required to...

In several books I have seen the statement that due to Heisenbergs principle no particle can be localized into a region of phase space smaller than ##(2 \pi \hbar)^3##. However, Heisenbergs uncertainty principle states that ##dx dp \geq \hbar/2## -- so a direct translation of this should imply...

$a,b,c>0$ $a+b+c=k$ find:$min(\sqrt{a^2+b^2}+\sqrt{b^2+c^2}+\sqrt{c^2+a^2})$

Can someone either derive or point me to a derivation of Møller's formula for the relativistic minimum radius of a rotating body? I've been searching for about an hour and it's driving me crazy! The only "minimum radius" equation I've seen imposes the speed limit c on a classical rotating body...

Hi :-) I'm currently learning about wave interference and came across two phrases I can't seem to find the meaning of; first order minimum and second order minimum. What do they mean an how are they used? I presume they are for the order of destructive interference or something?

Homework Statement http://puu.sh/bz0km/092f2d8781.png Homework Equations h^2/2ma^2 The Attempt at a Solution I've found the uncertainty of the kinetic energy through many means, and I'm confident that it's .052MeV. The easiest method that gave me this answer was: using...

Homework Statement A parallel beam of monochromatic light of wavelength 580nm is incidentally normal on a diffraction grating. The separation between successive lines on the grating is 0.7μm as shown in the figure. please refer to the photo , i am having problem with part (a) Homework...

Homework Statement Let X and Y be independent and suppose that each has a Uniform (0,10) distribution. Let Z = min{X, Y }. Find the density fZ(z) for Z. Homework Equations The Attempt at a Solution i'm sorry but i really don't know how to handle this.

Homework Statement For an electron in a uniform magnetic field, say B\hat{z} with no angular momentum, the Hamiltonian can be expressed as \hat{H}=\frac{1}{2m}\Big(\hat{p}_x^2+\frac{mω^2}{2}\hat{x}^2\Big)+\frac{1}{2m}\Big(\hat{p}_y^2+\frac{mω^2}{2}\hat{y}^2\Big) Which is equivalent to two...

So this looks really easy, but I can't get the right answer. It asks you to find the minimum acceleration from the graph: http://s22.postimg.org/f5dutd5ap/pic.png. This is of course the point where the slope is the smallest, and this is from t = 3-4 s or t = 4-5 s, depending on whether you want...

Hi, i am wondering how do you calculate the minimum film thickness between two plates, one smooth surface and another surface with a square microasperity. i am just very confused as to how do you determine the film thickness in between them. I have attached a paper which has a graph on...

I need to know a realistic minimum biaxial tension per unit length - in N/m - for the surface of a membrane which is 27.4 mm square - with surface density 0.0912 kg/m^2 - so that it could be vertical and remain tense so that mode shapes due incoming acoustic energy would remain intact (if the...

Homework Statement How wide is a single slit that gives its first minimum at 90°? Homework Equations øp=p(λ/a) The Attempt at a Solution Not quite sure what the answer is looking for but I'd guess I would need to solve for "a." So... 90°=(λ/a) Is there any more...

Given $a_1,...,a_n$, find the minimum value of $\sum_{i}^{n}(x-a_i)^2$ No idea how to do it. I was thinking maybe when $x-a_i=0$, but I think $x$ is constant so it won't work...unless the series $a_n$ is constant too...Tiny hint please :D?

Hi, I'm just wondering what are the minimum requirements for an international publication/conference/proceedings. E.g. impact factor

I'm reading the book The Theoretical Minimum. I wonder if two one of the problems in the book can be thought of graphically. The mathematical solution didn't even occur to me, although it make perfect sense and probably should have been obvious. 1. Can you explain why the dot product of two...

Without using the calculus, determine the minimum of $f(x)=(x^2-6)(x^2-8)(x^2-10)(x^2-12)+(6\cdot 8\cdot 10\cdot 12)$.

What is the minimum speed at which electrons can be emitted? Why is it I never heard of really slow moving electrons, like 10 meters per second slow?

Heey guys, I have a problem. I want to calculate the minimum time i have to activate a (latching)solenoid so that its final velocity is 0 m/s when it hits the inside. Well I know the following things: F= m*a I know the force and the mass, so a can be calculated. V = a*t. the average...

Principle: 10K Interest: 10% compounded annually Time: Over five years What is the total cost of all of this factored in? Could I get the formula so I can use it to apply to a real problem?

Homework Statement Problem is posted as imageHomework Equations The Attempt at a Solution Hello, I am having some confusion over what is meant by 'type in the boxes the minimum value of the expression'. Does that mean take the derivative of the function? Or does that mean the value at which...

Homework Statement show rectangular box of given volume has minimum surface area when the box is a cube [gotta show it with partial derivatives to minimize] Homework Equations surface area = 2(wl+hl+hw) volume = whl The Attempt at a Solution so this is the one I would be minimizing...

The quadratic polynomial $ax^2+bx+c$ has two distinct roots $p$ and $q$, with $a,\,b,\,c$ are positive integers and with $p>0$ and $q<1$. Find the minimum possible value of $a$.

Hello everyone, I am currently reading chapter two, section 3 of Griffiths Quantum Mechanics textbook. Here is an excerpt that is giving me some difficulty: "Formally, if we expand V(x) in a Taylor series about the minimum: V(x) = V(x_0) + V'(x_0) (x-x_0) + \frac{1}{2} V''(x_0)(x-x_0)^2...

Homework Statement Determine the minimum value of the force F for which the systems start moving. Assume M1 = 1kg, M2 = 2kg, Us = 0.3. Solution: F = 9; F = 6N My problem is that i don't know the forces acting on wheel. Homework Equations The Attempt at a Solution M1 : F -...

Homework Statement Show that the maximum and minimum values of y occurs when x^3=8+- 2(14)^1/2 Homework Equations The Attempt at a Solution

I am using the book Electronic Communication Systems by Wayne Tomasi: I had a problem with a certain part of the book: The book gives the formula for the minimum nyquist bandwidth as: " The minimum theoretical bandwidth necessary to propagate a signal is called the minimum Nyquist bandwidth...

Hello all, I have this tricky question, I think I got the idea, just wish to confirm. If the function \[z=x\cdot ln(1+y)+a(x^{2}+y^{2})\] has a local minimum at (0,0), then: (choose correct answer) 1) a<-0.5 2) a>0 3) a>0.5 4) -0.5<a<0.5 5) a>0.5 or a<-0.5 What I did, is calculate the...

I have what I think is probably a basic question from probability and statistics (about which I'm pretty ignorant). If I have a set of projectile trajectories that were generated by a Monte Carlo process, and I'd like to know the probability the projectile will come within distance d of some...

Homework Statement At what time t does the speed of the particle moving in space with its position function r(t)=##<t^2, 3t, t^2 - 8t>## have its minimum value? Homework Equations Derivative, speed The Attempt at a Solution Found derivative. r'=<2t, 3, 2t-8> Found speed...