Minimum Definition and 1000 Threads

F=ILB F=(48)(.76)B F/36.48=B I am stuck at how to find F, is there a different formula I am missing?

On object 2: There are only 2 horizontal forces - Friction and Tension (of the spring). T = km2g On Object 1: There are 3 horizontal forces and the minimum value for F is when: F - km1g - km2g = 0 F = kg(m1 + m2) However, Solution is: F = kg(m1 + 0.5 m2) Any opinion?

Hi, just thinking about a possible project and it may involve bolting aluminium plates together and putting a very small voltage across them. If I take two plates of aluminium, leave them to oxidise in air (we all know Al forms a surface layer) then is there a minimum voltage that will flow...

Homework Statement Homework Equations m2 = E2 - p2 ([/B]The Attempt at a Solution I got stuck by not knowing how to handle the frames and I thought you can view the Z boson (CoM) frame, but then you simply get that mz = 2me

<Moderator's note: Member has been informed to separate different question into different threads in the future.> 1. Homework Statement Please see picture attached... The diagram shows the curve with equation y = f (x) The coordinates of the minimum point of the curve are (–2, –1) (a) Write...

Homework Statement A person of mass ##m## stands at the left end of a boat of mass ##M## and length ##L##. Both the person and the boat are initially at rest. The coefficient of kinetic friction between the boat and the water is ##\mu##. If the person starts moving to the right, what is the...

Homework Statement In the far future, humans have built a space elevator as a cheap means of access to space. However before that could be done, a few basic principles had to be worked out. . . a) What is the minimum initial speed (in an Earth-centered inertial reference frame) needed for an...

Here's the problem: https://i.stack.imgur.com/rUVvu.png What I did: [2]: https://i.stack.imgur.com/AX2Ye.png [3]: https://i.stack.imgur.com/K1Zbi.png To those who could not understand what I read: So basically I used some geometry to to get $l_1$ and $l_2$ in terms of $r$ and the assumed...

Homework Statement After a free expansion to quadruple its volume, a mole of ideal diatomic gas is compressed back to its original volume isobarically and then cooled down to its original temperature. What is the minimum heat removed from the gas in the final step to restoring its state...

I have the following sequence: $x_{n}=(-1)^{n-1}\cdot \left(2+\frac{3}{n}\right),\forall n\in \mathbb{N^{*}}$ I need to choose from: A. $x_{n}$ is a monotonic sequence B. $x_{n}$ limit is $2$ C. $x_{n}$ minimum is $-\frac{7}{2}$ and the maximum is $5$ D. $x_{n}$ minimum is $-2$ and the maximum...

Homework Statement [/B] Two blocks A and B of masses m and M are connected to the two ends of a string passing over a pulley. B lies on plane inclined at angle theta with the horizontal and A is hanging freely as shown. The coefficient of static friction between B and the plane is us. Find the...

Hi, for those who don't know, Landau (Lev Davidovitch Landau) had a famous exam called "The theoretical minimum". That exam had to be passed by any future grad-student of his. That test was extremely extensive and difficult, and the student was supposed to be knowledgeable about many fields of...

Homework Statement This was a coding challenge, and I've already completed it. But I feel there must be a better solution to my approach at the moment. Especially maybe there's a mathematical approach. You have 3 sizes of boxes, small, medium, large: small: holds 3 items medium: holds 5 items...

Homework Statement For a physics experiment I need to find the uncertainties and I am using the angle of minimum derivation formula: The value of A=60° and one of the values of D is 29.7° which has a uncertainty of ±2 (I know it's a very high value) Homework Equations How do I calculate the...

We all know that our CO2 emissions will warm the planet. However I am wondering to what extent do climate models include the view that we might be heading to a new Maunder Minimum? https://www.nextbigfuture.com/2018/11/winter-is-coming-super-grand-solar-minimum.html Will this buy us a bit more...

Homework Statement At a given time ##t=0##, a car 1 moving with constant velocity ##v_{1}## breaks with constant deceleration ##d##. Another car 2 at a distance ##L## behind car 1 and traveling with constant acceleration ##a_{2}## and velocity ##v_{2}## at ##t=0## brakes immediately as soon as...

Homework Statement The operating cost of a truck is 12+(x/6) per km, when the truck travels x km/hr. If the driver earns 6 rupees (*or whatever currency your country has) per hour, what is the most economic speed to operate the truck on a 400 km road? Also, due to weather, the truck can travel...

Homework Statement A particle moves periodically around an ellipse of equation ##\frac{x^{2}}{a^{2}}+\frac{y^{2}}{b^{2}}=1##. You can assume ##a>b##. The ##x## and ##y## components of the particle's velocity can never exceed ##v## at any point. What is the minimum possible period of the...

Homework Statement I set the derivative to 0. i get 1 real root a max point and 2 imaginary. How can i find that local min? what techniques are available?

Homework Statement A rigid cube in the figure moves in space. At a certain time ##t## its front face ##ABCD## is vertical and the velocity of vertex ##A## is vertical down ##v## while the velocity of its vertex ##D## makes an angle with the vertical and has magnitude ##v_{2}## while lying on...

Homework Statement [/B] Homework Equations Drawing a diagram for the forces is the easy part. I am not sure I am doing the equation of the sum of the torques well. The Attempt at a Solution This is my attempt for the forces[/B] And this for the torques:

Homework Statement λ = 240 nm D = 2.40 m We are supposed to find the angle resolution (minimum angular distance between two objects so we still see them as two separate objects) to the telescope for ultraviolet light with wavelength 240 nm Homework Equations The equation that I used is θ =...

I am an IT student and working on a project, an automated system. It's not for a physics class. I can't say exactly what the system can do. But it uses Arduino to dispense servings of grains on a given schedule. I am more of a programmer than a physicist, I am looking for help on this. 1...

Homework Statement A wire pattern is inserted into a ##10##cm square by making a horizontal line in the middle of the square (not all the way across and with length ##x##) and connecting the ends of this line to the closest two corners. What is the minimum value of ##x##? Homework EquationsThe...

Homework Statement [/B] ##m=3kg## ##M=2kg## Coefficient of static friction between m and M ##\mu_1 = 0.6## Coefficient of static friction between M and the ground ##\mu_2 = 0.8##. The rope is weightless, does not stretch, and the wheel is frictionless. What is the maximum force ##F## that...

Homework Statement We have two cars moving like the picture. we want to find their minimum distance using relative motion. I) Consider a coordinate system on M, which has two axis. one axis is in direction of MP and the other is perpendicular to that (Something like r_hat and θ_hat). Find the...

Homework Statement [/B] 2. Homework Equations Fs = Nμ W = mg Fy = Fsin(θ) Fx = Fcos(θ) The Attempt at a Solution [/B] Hello all at PhysicsForums, I have a question on angled force and static friction. From my attempt below, I think I have found the maximum force required and would need...

Homework Statement There is a table, and a napkin on it. The napkin has a mass mn=71.6 g. On the napkin, there is a tea cup with mass mc=104.6 g. What is the minimum force required for someone to pull the napkin out from under the tea cup? Assume that between the table and the napkin the...

Homework Statement Is there a minimum value for the total energy of the electron (in this analysis)? The previous parts: Use Larmor formula to find ##\frac{|\Delta E|}{K}##, where ##|\Delta E|## is the energy lost per revolution. the result is ##\frac{8\pi v^3}{3c^3}##. ##\frac{v(r)}{c}## was...

Homework Statement An ambulance driver is rushing a patient to the hospital. While traveling at 70 km/h, she notices the traffic light at the upcoming intersections has turned amber. To reach the intersection before the light turns red, she must travel 58 m in 2.5 s. 1. What minimum...

Homework Statement The objects are set free from the scenario shown in the attached image. Their masses have been given and they are under the effect of gravity. The length of the string has been shown in the figure. If the two blocks cross each other, then we need to determine the minimum...

Homework Statement If ax2 - bx + 5 = 0 does not have two distinct real roots, find the minimum value of 5a + b. 2. Homework Equations The Quadratic Formula The Attempt at a Solution Here, D = b2 - 4a(5) = b2 - 20a D ≤ 0 ⇒ b2 ≤ 20a ⇒ b ≤ ±2√(5a) Also, an obvious observation is that b ≤ 0...

Homework Statement A stunt motorcyclist has to jump across a river 7.0 m wide from a ramp on one side with incline of 10 degrees. (a) What minimum speed the motorcycle must have to successfully land on the opposite side of the river? (b) How long will the motorcyclist be in the air? (Assume...

Homework Statement Find the minimum value of the area of the region under the curve ## y=4x - x^3 ## from ##x=a## to ##x=a+1##, for all ##a>0##. This problem is from Stewart's Calculus Homework Equations Finding the area under the curve... The Attempt at a Solution I can set up the equation...

Hello all. I am conducting a simple research project, and am having a little trouble with the math for paschen's law. my question is. At 74762 Microns of pressure, using pure Neon gas, what is the electrode spacing in mm for the minimum breakdown voltage of that gas? Thank you.

Hey! :o Let $a_1, a_2, \ldots , a_k\in \mathbb{R}^n$ and $f:\mathbb{R}^n\rightarrow \mathbb{R}$ defined by $\displaystyle{f(x)=\sum_{j=1}^k\|x-a_j\|^2}$ with the euclidean norm $\|\cdot \|$. Show that f has an uniquely defined global minimum and calculate it. I have done the following...

Homework Statement Homework EquationsThe Attempt at a Solution This problem belongs to the topic "calculus of variation ". The fundamental problem of “calculus of variation” is to find a function y(x) such that the integral ## I = \int_{x_i }^{ x_f} \phi (y’, y, x) ~d x ## is extremum...

Hello guys, In 90% of the papers I've read about diferent ways to achieve generalizations of the Proca action I've found there's a common condition that has to be satisfied, i.e: The number of degrees of freedom allowed to be propagated by the theory has to be three at most (two if the fields...

Homework Statement A factory is hiring ##m## employees. A number ##n > m## of candidates applied to the job. They need to answer an exam consisting of questions all of equal weight. A candidate is selected to the next step (the interview) if he/she achieves a minimum of ##c## points in the...

Hello. I am attempting to build a large vacuum chamber for woodworking (used to infuse wood with resin/stabilizer). I would like to use a cast iron bathtub, similar to the one pictured as the vessel. I would ideally like to use a clear acrylic lid (with a rubber gasket) like the one on my...

As part of my work, I'm making use of the familiar properties of function minima/maxima in a way which I can't seem to find in the literature. I was hoping that by describing it here, someone else might recognise it and be able to point me to a citation. I think it's highly unlikely that I'm the...

I have a thin tube (4 mm diameter) sticking out of a small box (a bit larger than a matchbox). I want to use this tube to measure the dynamic pressure. How long must the tube be for the results to be reasonably accurate? Intuition tells me the working end of the tube should be kept in the...

Homework Statement A point particle of mass m and charge q(>0) approaches to a point particle Q(>0) at a fixed position. When the distance between the two particles is L, the speed of the moving particle is v. The permittivity of the vacuum is denoted as Epsilon0. Find the minimum distance...

Homework Statement The first exercise in Susskind and Hrabovsky's The Theoretical Minimum is one that, in the words of Susskind, "is designed to make you think, more than it is designed to test you." The exercise asks: Homework Equations In the prior paragraph, the authors define the notion...

Hello to everyone who's reading this. The problem I need help with is the following.: Homework Statement "Simplify to obtain minimum SOP. F(A, B, C, D) = A’B’CD’+AC’D’+ABC’+AB’C+AB’C+BC’D" The problem stated above has two provided solutions, the "main" one and the "alternate" one. I'm...

Hey! :o We have the function $f: (\mathbb{R}^2,\|\cdot\|_2)\rightarrow (\mathbb{R},|\cdot |)$ with \begin{equation*}f(x,y)=\begin{cases}y-x & y\geq x^2 \\ 0 & y<x^2\end{cases}\end{equation*} I have shown that $f(x,y)$ is discontinuous at the points $(x,x^2)$ with $x\neq 0,1$ and continuous at...

Does anyone know if or when Dr Susskind is coming out with a “ Theoretical Minimum Quantum Field Theory “ ?

Homework Statement You should shoot a basketball at the angle ##\theta## requiring minimum speed. Avoid line drives and rainbows. Shooting from (0, 0) with the basket at (a, b), minimize ##f(\theta)= 1/(a \sin (\theta) \cos (\theta) -b \cos^2 (\theta))##. (a) If b =0 you are level with the...

Homework Statement Show that A is a scalar matrix kI if and only if the minimum polynomial of A is m(t) = t-k Homework EquationsThe Attempt at a Solution f(A) is monic f(A) = 0 since A = kI Next we must show that deg(g) < deg(f) I guess I'm not sure where g comes from. Is it merely an...

Hi, I am trying to solve a control problem where I have to minimize the fuel consumption of a vehicle: $$J=\int_{0}^{T} L(x(t), u(t),t) + g(x(T),T)dt$$ ##L(u(t),v(t))=\sum\limits_{i,j=0}^{2} K_{i,j} u(t)^i v(t)^j ## is convex (quadratic) and the term ##g(x(T),T)## is to have a constraint in the...