Max Definition and 1000 Threads

Homework Statement A line passes through (3,4). What is the maximum value of x+y? Homework Equations y = mx + bThe Attempt at a Solution So I set up a system of equations, m3+b =4; b = Y; mX + b = 0. Then I plugged my values for X and Y into m3+b = 4.. The weird thing is though...

Homework Statement Hey, so i need some help trying to find the local max and min points for y = sinxcox3x Homework Equations The Attempt at a Solution I know i need to find the first and 2nd derivative but i do not know if i am doing it right. I also do not know what to do after wards. my...

Homework Statement The coefficient of static friction between a small coin and a turntable is 0.30. The turntable rotates at 33.3 RPM. What is the max distance from the center of the turntable at which the coin will not slide? Homework Equations Fs max =μs (FN) V = ω (r) a=(V^2)...

riddle question " max profit + units " Homework Statement There is no demand for a new brand of mobile phones if the price is 20 $ or more. For each drop of 1 $ in the price, the demand increases by 500 units.The cost of producing x units is (12x + 2000)$. How many phones should be produced...

Homework Statement "The initial speed of a stone projected vertically upwards is 21.0m/s a)What is the maximum height it will reach? b) How long does it take to reach the highest point and what is the total time which it is in the air?" Relative information: a=9.8 m/s/s u=21.0...

In MATLAB I have a function which calculates P04 for different values of i,j, and k providing a 8x89x89 matrix of values. I am trying to find the max P04 for each value of i and the corresponding j and k values. Here are my for loops: for i = 1:1:8; M1(i) = 2+0.1*i; for j = 1:1:89...

max speed --> electron 1. An electron starts from rest 15.0 cm from the center of a uniformly charged insulating sphere of radius 10.0 cm and total negative charge -3.00 μC.What is the maximum speed (in m/s) the electron can reach after releasing it? (Note: Assume a reference level of the...

Homework Statement Given three 4 ohms resistors rated at 20 W, find the maximum potential difference that can be applied if they are connected all in parallel... Homework Equations The Attempt at a Solution so in this case i first calculated the current using P= I^2R, which gives...

Homework Statement After how many time constants does the current in the figure below ( http://www.webassign.net/gianpse3/30-06.gif ) reach the following values? (a) within 67 percent of its maximum value (b) within 6.7 percent of its maximum value (c) within 0.67 percent of...

Homework Statement In an oscillating LC circuit, L = 2.93 mH and C = 3.21 μF. At t = 0 the charge on the capacitor is zero and the current is 2.14 A. What is the maximum charge (in C) that will appear on the capacitor? Homework Equations I know that for an LC Circuit, the charge q at...

x in (0,pi]; f(x) = sin(x)-x2; f'(x) = cos(x) - 2x; f'(x) = 0 ==> cos(x) - 2x = 0; since |cos(x)| ≤ 1, cos(x) - 2x ≤ 1 - 2x; Now 1-2x = 0 <==> x = 1/2; f'(1/4) = cos(1/4) - 2*(1/4) > 0 and f'(3/4) = cos(3/4) - 2*(3/4) < 0; ==> x = 1/2 is maximum and f'(x) ≤ 1/2; Is my...

For any constant c, define the function f-subscript c withe formula f-subscript c(x)= x^3 + 2x^2 + cx a)graph y= f-subscript c(x) for these values of the parameter c: c = -1,0,1,2,3,4. What are the similarity and differences among the graphs, and how do the graphs change as the parameter...

i posted it in general physics and got not answer. maybe this is the right place for this. thanks here is a question for max dynamic factor for sinusoidal load F*sin(at). say the natural frequency is b for a mass. then the max DLF considering damping is DLF=1/(1-(a/b)^2) when a>>b...

Homework Statement You are designing a delivery ramp for crates containing exercise equipment. The crates of weight 1500 N will move with speed 2.2 m/s at the top of a ramp that slopes downward at an angle 23.0 degrees. The ramp will exert a 586 N force of kinetic friction on each crate, and...

I'm observing the circular process of a heat engine. It's p-v diagram is So between points 3 and 4 the heat is extracted. That causes losses since the efficiency if given by \eta =1- \frac {Q_c} {Q_h} Where Qh is the heat the heat source has given and Q_c the amount of heat that...

Homework Statement A plank is supported from two points. How far can a gril that weights 48 kg walk on the plank before the plank starts to rotate?. Middle of plank is its gravity point. Picture: I have added a picture that might tell a bit more(not so good at English :/)...

I am considering PhD positions in Physics. Can you guys tell me how reputable Max Planck institute (Heidelberg) is compared to top universities? Thank you.

I need to make to functions in java that gives the maxim and minin of the Parabola polynom ax2+bx+c for an interval of two given points. I have no Idea how to make this algorithm , could you help ? I have come to something like this :

Homework Statement A projectile os launched with velocity of 200m/s at an angle of 45deg to the horizontal. Calculate: a) the maximum height reached b) the time of flight c) the range Homework Equations v^2=u^2+2as s=ut+1/2 at^2 The Attempt at a Solution I know the first 2 but...

Homework Statement On level ground, what is the maximum range (in m) of a cannon with muzzle speed 322 m/s? Please take a look at this: http://i995.photobucket.com/albums/af79/huybinhs/cannon2.gif Homework Equations R = (V0^2 * sin2angles)/g The Attempt at a Solution...

Homework Statement A model rocket initially at rest on the ground is fired vertically upward, and the engine thrust produces a constant acceleration a = 40 m/s2. After running for 2.5 s the engine is cut off and then the rocket is in free fall. (a) Find the maximum height that the rocket...

Homework Statement If the maximum tension either rope can sustain without breaking is 4000 N, determine the maximum value of the hanging weight that these ropes can safely support. You can ignore the weight of the ropes and the steel cable. The Attempt at a Solution I figured out that the...

Homework Statement max{nte-nt: t in [0,1]} = ? Homework Equations The Attempt at a Solution if f(t) = nte-nt f '(t)= ne-nt - te-nt = e-nt(n-t) set equal to zero to get critical points: 0 = = e-nt(n-t) => two critical points: t1 = n and t2 = -1/n; plugging the cp's...

Homework Statement An object is thrown vertically upward such that it has a speed of 47 m/s when it reaches two thirds of its maximum height above launch point. Find maximum height h. Homework Equations V^2-Vo^2 = 2gh or V^2-Vo^2 = 2g(1/3H)? The Attempt at a Solution Final...

Hi, I have this question for a college assignment. It involves 3 'unknowns' (not 3 variables, since 2 are constants). The main difficulty I am having is inexperience with max and min problems where you cannot fully evalaute the solution. I think I have made a reasonable attempt at a...

Homework Statement A 32 kg cannon ball is fired from a cannon with muzzle speed of 1360 m/s at an angle of 44◦ with the horizontal. The acceleration of gravity is 9.8 m/s2 . What is the total mechanical energy at the maximum height of the ball? Answer in units of J. Homework Equations...

Homework Statement The object is to fold and then cut square corners from a standard 8.5 by 11 inch sheet of paper to create a suitcase of maximal volume Homework Equations V=L*W*H SA=2LW+2LH+2WH The Attempt at a Solution 93.5=2(8.5-2x)(11-2x)+2(11-2x)2x+2(2x)(8.5-2x) x=1.375...

how can i work out the maximum shear stress of EN 19 alloy steel? i need this in order to work out the minimum shaft diameter that will be capable of withstanding the torque applied to it.

A cylindrical torsion bar made of steel (E = 209 GPa) with diameter of 20mm. The allowable shear stress for this material is 200 MPa what is the max torque that can be safely applied to this bar. \tau = Tr / J \tau = shear stress T = torque r = radius J= second polar moment of area...

Ok, so for a summative project, my group has to build a catapult which must use elastic bands to propel an object. I have the energy, force, and maximum stretch distance of the elastic band. The values are 8 joules, 16 Newtons, and 0.5 meters. The catapult is not built yet, so I can't give any...

Hi, I have a small DC dynamo (with no spec sheet) which i digitally sample to find it's voltage at any given time. I want to display theoretical max power output, how can I calculate this? Can I use P=V^2/R where V is measured. How do I calculate R? I read a wikipedia article which says to...

Homework Statement Find the maximum Tension in the rope that supports the bungie jumper. mass of the jumper is 75kg. neglet air resistance. Homework Equations would it be Fnet = ma Fgravity - F Tension = ma The Attempt at a Solution I am not sure how to...

Homework Statement Find the maximum Tension in the rope that supports the bungie jumper. mass of the jumper is 75kg. neglet air resistance. Homework Equations would it be Fnet = ma Fgravity - F Tension = ma The Attempt at a Solution I am not sure how to...

Homework Statement If S\subsetR is finite and non-empty, then S has a maximum. Can someone look over this? I struggled a bit in my first proof class, which is why I am asking for help, so I really am unsure if this is right at all. Let S={1} So 1\inR such that for all x\inS, 1\geqx So...

I'm trying to calculate the max load of a rack made of 3X3X1/4 steel tube. It is 8ft long and 4ft wide. I just want to calculate the max load (distributed load) in bending cross the 8ft and also in compression for the legs. i can't find the right formulas. can anyone help? so far i what i...

Homework Statement Find the maximum and minimum values of 4cos\theta-3sin\theta. Homework Equations I have no idea. The Attempt at a Solution I have no idea how to do this question Please help me!

Dear Experts, I am a gradute engineer posting here for the first time. I have a query regarding the simple problem to which i cannot seem to get the correct Max bending moment. Here is the problem. A beam of length L rigidly clamped at both ends with a point load F in the centre, i.e, at...

Homework Statement String on the violin is made of steel wire with a diameter of 0.25 mm. With what force must the string be strained (stretched) so that its basic frequency will equal 660 Hz (E-string)? What is the maximum velocity and acceleration of the parts of the string, if we evoke...

stone tied to string whirled. Max string tension?? Homework Statement A stone of mass m at the end of a string of length l is whirled in a vertical circle at a constant speed when will the tension in the string be maximum?Homework Equations a) at the top of the circle b) halfway down from the...

Homework Statement I'm to design a crane, and therefore I need to find the reactions in the jib and also make the crane stable. 1. I need to find the max. load that the crane is able to lift. Therefore i have to find the reactions where the horisontal and vertical boom is meeting. 2. I need...

The position of a .64 kg mass undergoing simple harmonic motion is given by x(t) = (.16 m)cos(\pit/16). What is the maximum net force on the mass as it oscillates? (hints: First, match the quantities in the equation above to x(t) = Acos(\omegat). Next, recall that the max. net force equals the...

Homework Statement y = 2x^2-14x Homework Equations The Attempt at a Solution y' = 4x - 14 4x - 14 = 0 x = 14/4 f(14/4) = 2(14/4)^2 - 14 (14/4) = -49/2 I don't know how to continue from there. ((14/4), (-49/2)) is my critical point?

Homework Statement Let y be the the solution of the initial value problem. The maximum value of y is? y" + y = -sin(2x) y(0) = 0 y'(0) = 0 Homework Equations N/A The Attempt at a Solution Factor out original equation to find general equation. r2 + 1 = 0 r = 0 + i; 0- i Thus...

Hi, I understand that the local max of a function is the point at which the y value of the function is larger than the neighbouring y values of the function. Say we're considering the local max at a of a function f(x). Does the function have to exist on both sides of a for (a,f(a)) to be a...

Homework Statement What is the maximum height that the body reaches when thrown vertically upwards from the surface of the Earth at a velocity of 5km/s, if we neglect the impact of the atmosphere? The radius of the Earth is r= 6400km; the acceleration of gravity on the surface is g = 10...

Homework Statement The temperature at a point (x, y) on a metal plate is T(x, y) = 4x^2 − 4xy + y^2 . An ant, walking on the plate, traverses a circle of radius 5 centered at the origin. Using the method of Lagrange multipliers, find the highest and lowest temperatures encountered by the...

I need help with this problem please. Finding the max volume of a box with an open lid. Using a 20 in by 20 inch sheet of cardboard and cutting out the corners. Equations i been using: Volume: Length*Width*height Area: L*W Perimeter: 2L+2W Can someone help me get started

Problem: An 8 m, 200 N uniform ladder rests against a smooth wall. The coefficient of static friction between the ladder and the ground is .45, and the ladder makes a 60 degree angle with the ground. How far up can an 800 N person climb before the ladder begins to slip? a. 7.8 m b. 6.8 m c. 5.8...

Homework Statement A 200 g ball is dropped from a height of 1.9 m, bounces on a hard floor, and rebounds to a height of 1.5 m. The figure shows the impulse received from the floor. What maximum force does the floor exert on the ball? Homework Equations Kinetics: x-xo = vot +...