Maximum Definition and 1000 Threads

Homework Statement Force of jet= A(r(t))4/3 A: constant determined by the fighter model in the class being considered and the drag force on the plane r(t): the rate of fuel consumption as a function of time Consider 3 possible situations for r(t): 1. when the rate is constant for the...

Homework Statement See attached photo Homework Equations Stress = F/A Area = pi d^3 / 4 Sum F h = 0, Sum F v = 0, Sum M = 0 The Attempt at a Solution Hey everyone, after reading the question a number of times and not knowing for certain where to start, I figured because the stress and area...

Homework Statement A constant voltage source V with internal resistance r is connected to a load resistor R. The dissipated power by the resistor R is P=RV^2/(R+r)^2. Show that the maximum power dissipated by the resistor R is achieved when R = r. The maximum of P with respect to R is achieved...

Homework Statement Police will be sent to conduct their work on a site which is a rectangular region of sides 3.9 km and 9.1 km. To make their work easier, the region will be divided into square regions, each one having the largest possible area, and such that their sum equals the original...

Sorry if I didn't post this at the right place. Hi all, I have a problem that I am not able to solve. I hope you guys can help me! I am creating a suction cup to grab and lift an object with a flexible surface made of out silicone The suction cup is also made out of some sort of flexible...

https://www.physicsforums.com/attachments/220647 Homework Statement Two uniform planks each of mass 10Kg and length 2m, are arranged as shown in the picture. Find the maximum value of x for which the top plank will remain in equlibrium. Homework Equations F= (mgl)/hThe Attempt at a Solution I...

Homework Statement Two loudspeakers are placed 3.00 m apart horizontally.They emit 425 Hz sounds, in phase. A microphone is placed d= 3.20 mid distant from a point midway between the two speakers, where an intensity maximum is recorded. (a) How far must the microphone be moved to the right to...

Homework Statement Finding the maximum mass ##M_x## which can be made from a collision of identical particles with mass ##m##, in the laboratory frame, in which one particle is at rest and the other one has energy ##E##. The reaction is the following: ##a+b \rightarrow a+b+x##.The Attempt at a...

Homework Statement 14.100 Calculate the maximum and minimum distances in kilometres between the centers of the Earth and moon, taking the eccentricity of the moon's orbit into account. Use the data given in Prob. 14.99 Homework EquationsThe Attempt at a Solution Can you check my solution...

Homework Statement Determine the Full Width Half Maximum (FWHM) using the single coil equation and fitting parameters. The FWHM is the measure of how broad (wide) a signal is before it loses half of its intensity. In this case, its a measure of the distance spanned before the magnetic field...

Homework Statement In order to solve a question, I need to find the minimum and maximum resultant of three vectors, their magnitudes are given to me. Homework Equations Magnitude of vector A = 1 Magnitude of vector B = 3 Magnitude of vector A = 5 The Attempt at a Solution The maximum part was...

Homework Statement What is the maximum acceleration the train can achieve? Engine effect=6500kW μ(Friction Coefficient (between rails and wheels))=0.45 g=9.82N/kg m(Train weight)=120,000kg α=0 Homework Equations Fμ=Fn*μ Fn=cos(α)*m*g a=F/m The Attempt at a Solution We've used the equations...

A building has a water inlet and outlet. The static water pressure at the buildings water intake is 5 bar. I'm trying to determine how much water this outlet will deliver when its valve is fully open. In that state, the pipe size and length will result in a certain head loss that I can calculate...

Hey! :o I am looking at the Likelihood function. I have understood how we define that function, but having find the maximum of the Likelihood estimation, what is the meaning of that? What information do we have, when we have found the $\theta$ so that the Likelihood function L is maximized...

Homework Statement Homework Equations I drew phasors and got the answer. Angle between V and I is 60 degrees. Cosine of 60 is 0.5. Then I multiplied V and I and divided it by 2.The Attempt at a Solution I got answer 62.5. But I'm not sure if values of V and I given are rms values or maximum...

https://www.sciencedaily.com/releases/2018/01/180116093650.htm This article gives a maximum weight of 2.16 solar masses, and an infinitesimal addition would turn it into a Black hole. I can not find a paper to support this article so do you think it is correct?

I have found in a literature that "For our purposes, all control rods in PWR are assumed fully out during normal core operation, which provides the maximum scram reactivity capability at all times." --What does it mean by "maximum scram reactivity capability"? --Has there any conservative...

Homework Statement Ans) F/k Homework EquationsThe Attempt at a Solution Consider only figure a) . I believe the given answer is wrong . The maximum extension should be 2F/k . F/k is the extension in the spring in the equilibrium position . Maximum extension should be double of that . Work...

Homework Statement Maximum power is transferred to variable load when: 1) RL = Rs 2) RL not equal to 0. and Rs = 0 3) RL = 0 and Rs not equal to 0 4) RL = Rs/2 Homework Equations Maximum power theorem RL = Rs The Attempt at a Solution But if Rs = 0, then current is maximum, so load get...

Homework Statement An oil-filled transformer has a c.m.r. of 500 kVA which allows it to run continuously in an ambient of 35°C with an oil temperature rise of 50°C. The transformer has a time constant of 1.5. hours and the ratio of copper losses to iron losses at c.m.r. is 1.5:1. After...

Hi, I'm quite stuck on this past paper question and would really appreciate some help on it. Below I have attached the questions and solutions; it asks me to determine where the maximum tensile and compressive strain in the beam using the bending moment diagram (attached as separate figure...

Homework Statement Homework EquationsThe Attempt at a SolutionTaking the engine to be a Carnot engine, ## \eta = \frac { T_h – T_c } {T_h} = \frac { W} {Q_h} ## ...(1) ## Q_h = C(T_h – T_f) ...(2) \\ Q_c = C(T_f – T_c) ...(3) \\ W = Q_h – Q_c = C(T_h + T_c – 2 T_f) ## ...(4)Solving...

Hi I've been googling maximum likelihood estimation. While I do understand how to compute it, I don't understand why maximizing the likelihood function will give us a good estimate of the actual parameter. In some cases, like the normal distribution, it seems almost obvious. However, in the...

The rider is cornering at maximum available lateral acceleration so he is not able to countersteer to the "inside" in order to bring the bike to the vertical position. So he decides to push down to the road with his knee to bring the bike up, does that unload the tires by countering gravity and...

Homework Statement This problem concerns a single slit diffraction experiment where Fraunhofer diffraction is observed on an observing screen via a positive converging lens with focal distance f. The diffraction pattern has a central maximum of width dy, and the vacuum wavelength of the light...

Homework Statement If I have an object with mass M. Place it on a spinning disk at radius R and the coefficient of friction is μ what is the maximum velocity I can spin the disk without the object slipping? I have the actual values for the problem, but I'm much more interested in how to get...

A plate is riveted with a rivet having small rod like projection over the head and the point as shown in drawing.Considering we fix the plate to a vise,and then giving torque to the Rivet Rod;What will be the Maximum Torque the rivet can withstand without getting loosened and how to calculate...

Homework Statement A spring toy is launched from the ground at 2.3 m/s at an angle of 78° to the ground. What is the maximum height reached by the spring toy? Homework Equations Δt = 2(V1)Sinθ/(acceleration) ΔD = V1Δt + 1/2(acceleration)(Δt^2) The Attempt at a Solution First I solved for...

Homework Statement The exercise is this: The mass of the car is m=500 kg. The maximum speed of the car on flat road is v1=35 m/s and on 10 % up hill (tan(alpha)=0.1, alpha is with respect to flat) the maximum speed is v2=20 m/s. The friction force is double on up hill because it has been made...

Homework Statement Determine the point on a plane curve f(x) = ln x where the curvature is maximum.[/B]Homework Equations k(x) = || T ' (x) || / || r ' (x ) || k (x) = f '' (x) / [ 1 + ( f '' (x))2 ] 3/2[/B]The Attempt at a Solution f ' (x) = 1/x f " (x) = -1/x2 k(x) = 1/x2 / { [1 +...

Greetings All! I am not sure if this is the correct place to post this, but I think that since rocket fuel is considered a chemical reaction, this sections seems appropriate. Right, to the topic. Me and my team from the spaceflight society are looking forward to building a hybrid rocket fuelled...

Homework Statement I was asked to design a beam from the beginning to detailing . I encountered that the shear force for minimum links is greater than the maximum shear force , is it possible ? Homework EquationsThe Attempt at a Solution I have checked thru the working , it seems that...

Hello everyone! I was wanting to know if something like this was possible. I read (Wikipedia) that the moment a cylinder will burst is when the hoop stress is equal to the cylinder's tensile strength. It also appears that the thickness of the material doesn't matter. I don't see Young's...

Homework Statement A naval towed-array sonar comprises a line of ##80## transducers, equally spaced over a total length of ##120 m##, that is towed behind a ship so that it lies in a straight line just below the surface of the water. An adjustable phase delay can be introduced electronically...

Homework Statement Homework Equations At local minimum or maximum the first derivative equals zero The Attempt at a Solution a) $$f'=2x-\frac{a}{x^2},~~2\cdot 2-\frac{a}{4}=0~\rightarrow a=16$$ Near 0 from the left a/x gets large negative values, smaller than for a=16. that's my proof for...

Homework Statement Homework Equations First derivative=maxima/minima/vertical tangent/rising/falling The Attempt at a Solution The profit S: $$S=nx=\left[ \frac{a}{x-c}+\frac{b}{100-x} \right]x$$ $$S'=\frac{a}{x-c}+\frac{b}{100-x}+\left[ \frac{-a}{(x-c)^2}+\frac{-b}{(100-x)^2} \right]x$$...

Homework Statement Homework Equations First derivative=maxima/minima/vertical tangent/rising/falling Volume of a cone: ##~\displaystyle V=\frac{\pi}{3}r^2h## The Attempt at a Solution $$L=a^2+b^2~\rightarrow b^2=L-a^2$$ $$V=\frac{\pi}{3}a(L-a^2)$$...

Homework Statement Homework Equations First derivative=maxima/minima/vertical tangent/rising/falling The Attempt at a Solution a are the sides of the base and b is the height $$A=4ab+a^2,~~V=a^2b=a^2\frac{A-a^2}{4a}=...=\frac{1}{4}a(A-a^2)$$...

Homework Statement Homework Equations First derivative=maxima/minima/vertical tangent/rising/falling When f'(x)>0 → the function rises The Attempt at a Solution $$V=(15-2a)(8-2a)=4a^2-46a+120$$ $$V'=8a-46,~~V'=0\rightarrow a=5.75$$ But: ##~2a<8,~~V(a=4)=0## So 5.75>4 And: ##~V''=8## so it...

Homework Statement A 10g ball is fired at 6 m/s into a 280g pendulum. What maximum angle will the pendulum swing to if the effective radius of the pendulum is 28cm? Homework Equations How to find theta? The Attempt at a Solution I converted 28cm to 0.28m; 10g to 0.010kg; and 280g to 0.280kg...

Hi all. I am not a mechanical engineer but I've been working on an idea which consists of a linear shaft with Reciprocating motion. Since the device only works with rather a high speed shaft, I wanted to know what are the speed restrictions of a linear shaft? So let's give it some numbers. The...

Homework Statement I don't know how to do Question 2 part C. Homework Equations I know that E=hf and I know the photoelectric equation: hf = work function + 1/2mv^2The Attempt at a Solution I honestly don't have a clue how to do part c of question 2. I think it involves one of the two...

6d Anotherdisease hit the the chronically ill town of College Station, Texas. This time the percent of the population infected by the disease $t$ days after it hits town is approximateled by $$p(t)=10e^{-t/8},0 \le t \le 40$$ a. After how many days is the percent of the population infected a...

Homework Statement Show that \Gamma_T is maximum at E_a = \frac{N_aE}{N_a+N_b} Homework Equations The expression for \Gamma(E) when N\gg 1 \Gamma_T = C_aC_b exp \left( -\frac{E_a^2}{2N_a\mu_B^2h^2} \right) exp \left[ - \frac{(E-E_a)^2}{2N_b\mu_B^2H^2} \right] where C_a and C_b are...

Homework Statement Formulate a proof that the energy minimum principle implies the entropy maximum principle. That is, show that if the entropy were not maximum at constant energy then the enrgy could not be minimum at constant entropy. HINT: First show that the permissible increase in entropy...

Homework Statement Homework EquationsThe Attempt at a Solution Now, the input circuit is also biased as the transistor to work in the active region and without the biasing of the input circuit , the input circuit may get reversed biased during the negative half cycle of the signal voltage...

Homework Statement We are given that a spaceship converts mass directly to light (emitted backwards) in order to accelerate. If an energy mc^2 has been converted to light ( from the Earth's reference frame) then what is the final speed of the ship (w.r.t. Earth) if the ship's rest mass is M and...

1. Cuboid of height h is made out of material with density ρ=1000kg/m3 and it can endure highest pressure of σ=90kPa.Cuboid is falling from the height H. When the cuboid hits the ground its centre of mass is at the height h/2.Then starts deformation of the body. During the deformation centre of...

Hi, I can't seem to work out how angle of projection for maximum range comes out to be (pi/4 - Beta/2) This happens when the projectile is protected up the inclined plane. Similarly, I couldn't understand how the angle comes out to be (pi/4 + Beta/2) when the projectile is protected down the...

<mod: moved from intro> Hello all! This is my first post in this forum. I am struggling with the following question regarding a hair dryer. The hairdryer can be seen as a cilinder with a fan inside blowing air at speeds from the table below and 1 nichrome wire which heats up consuming different...