Homework Statement
A rectangular region of 125,000 sq ft is fenced off. A type of fencing costing $20 per foot was used along the back and front of the region. A fence costing $10 per foot was used for the other sides. What were the dimensions of the region that minimized the cost of the...
Homework Statement
Part (a) has already been solved and determined to be 5kΩ, which has been confirmed by the answer key.
The answer key also states that the maximum power able to be delivered to Ro is 957 µW, but doesn't give any workings or explanations on how to reach this answer...
hi there..i have a question...back at my work, we have a power supply which have a variable current and a variable voltage...my senior said, he have a ic board to check, and then he uses a 5 volt supply with unknown current on it to power up this board,
he then claims that you can supply the...
Homework Statement
Two identical particles, each of mass m are located on the x-axis at ## x=+x_0 ## and ## x = -x_0##. At what point (or points) on the y-axis is the magnitude of ##\vec g ## a maximum value and what is its value there?
Homework Equations
Formula for gravitational field...
Homework Statement
A radar receiver can be tuned to detect signals are different wavelengths. If the frequency difference between the minimum and maximum wavelength is 10 GHz and the minimum detected wavelength is 4910µm. What would be the maximum wavelength?
Homework Equations
λƒ=c
The...
Homework Statement
A mass of 0.36kg hangs motionless from a vertical spring whose length is 0.8m and whose unstretched length is 0.51m. Next, the mass is pulled down to where the spring has a length of 1.09m and given an initial speed upwards of...
Homework Statement
A laser emitting light with a wavelength of 560 nm is directed at a single slit, producing an interference pattern on a screen that is 3.0 m away. The central maximum is 5.0 cm wide. Determine the width of the slit.
I have two ideas of the answer but I'm not sure which is...
Homework Statement
The question is asking us to minimize the maximum bending moment by changing l3.
l1=3(m)
l2=6.5(m)
l4=12(m)
P1=1200(KN)
P2=2300(KN)
P3=410(KN)
and we know that obviously, 6.5<l3<12
Homework EquationsThe Attempt at a Solution
We made relevant cuts and acquired the equations...
Homework Statement
2. Homework Equations [/B]
I was given this info
r=1.5 m
d=3 m
F= 50
angle= 110 degreesThe Attempt at a Solution
T=Fsin
T= (1.5)(50)sin(110)
T=70 N
I attempted the solution^ to get (maximum) torque.
Homework Statement
"
A 1100 kg lift is suspended by a series of 24 steel cables of mean diameter 20mm. The cables are attached to the lift top and are arranged so that torsional vibration is minimised.If the cable is manufactured from steel with an elastic modulii of 185GN/m2 and elastic...
Homework Statement
A block of mass m1 slides along a frictionless table to the right with a speed of v1. A second mass M2 slides in the same direction with a speed of v2 such that it will collide with m1 which is in front of m2. Say that a spring of stiffness k is attached to one of the masses...
The scenario involves dropping something into a bucket of water. I'm trying to do an experiment where I have to figure out a relationship between the amount of water that leaves the bucket and a certain variable of the object that is dropped.
I'm wondering what could maximize the water that...
Homework Statement
A parallel circuit like that in the figure forms the tuning circuit for an AM radio. If the inductor has a value of 8.6×10-6 H, what must be the maximum and minimum values of the variable capacitor if the radio receives frequencies from 590k Hz to 1670k Hz?
a) Maximum C?
b)...
Hello! (Wave)
I am looking at the following exercise:
For each function $f(n)$ and for each time $t$ find the maximum size $n$ of the problem that can be solved in time $t$, assuming that the algorithm of the problem requires time $f(n)$ microseconds( 1 microsecond=$10^{-6}$ second)
Suppose...
Homework Statement
A cannon at ground level is shooting emergency packets to people stranded on the roof of a flooded building of height H=125 meters. The corner of the building is located a distance D=50 meters from the cannon. It is desired that the incoming packets are flying tangent to the...
Homework Statement
Homework Equations
Pmax = ((VTh)2)/(4RTh)
Rparallel = (R1R2)/(R1 + R2)
KCL ΣI = 0
KVL ΣV = 0
The Attempt at a Solution
Okay, so to find RTh, I remove all independent sources and set the "terminals" at R to have a 1A current running through them. Since there is a 30kΩ...
I want to know the maximum shear stress acting on the y-z face(plane). I already know all 6 stress components: Sxx, Syy, Szz, Sxy, Syz, Sxz. The shear components on the y-z face are Sxy and Sxz, which are orthogonal to each other. Is the maximum shear on this plane simply the greater of the two...
Homework Statement
Find the maximum value of f(z) = exp(z) over | z - (1 + i) | ≤ 1
Homework Equations
|f(z)| yields the maximum value
The Attempt at a Solution
f(z) = exp(x) ( cosy + i siny)
Unfortunately that's all I've got. I've seen examples with polynomials, but not with trigonometric...
Is there a physical explanation for why when given a differential equation with spatial derivative of spatial order 2m the maximum order of the essential (displacement) boundary condition is m, and the maximum order of the natural (force) boundary condition is 2m-1
for example, the equaiton...
Homework Statement
Let u = ∂f/∂x and v = ∂f/∂y. Use Lagrange's method to set up the equations necessary for finding the maxium of u^2 + v^2.
Homework EquationsThe Attempt at a Solution
I know how to minimize and maximize a function that's a subject to another one. I'm not quite sure what the...
Homework Statement
A stone weighing 1/2 lb is thrown upward from an initial height of 5 ft with an initial speed of 32 ft/s. Air resistance is proportional to speed, with k=1/128 lb-s/ft. Find the maximum height attained by the stone.
Homework Equations
None.
The Attempt at a Solution
Here's...
My gut instinct is that putting all the resistors in series will give max resistance, but I am not sure how to give a more rigorous either mathematical or just in words reasoning why. Or maybe I'm wrong! But it seems like the fraction introduced from parallel won't help
In any case, assume all...
Homework Statement
The variable resistor R in the ciruit is adjusted for maximum power to Ro. what percentage of total power developed in circuit is transferred to R.
Homework Equations
i=V/R
The Attempt at a Solution
So my goal is to put a "fake" charge across v/2(the dependent source) of 1A...
Homework Statement
Two blocks, each of mass m, are connected on a frictionless horizontal table by a spring of force constant k and equilibrium length L.
Find the maximum and minimum separation between the two blocks in terms of their maximum speed, vmax, relative to the table. (The two blocks...
Homework Statement
There are 3 masses ma= 50 kg, mb= 60kg, mc= 80kg. These masses are connected with a rope that affords a tension of 1000 N. On the mass 3 is applied a force F. Knowing that the tension between A and B TAB= 200 N. a)Find the acceleration b) find the maximal value of the force F...
Homework Statement
A 50g block is attached to a vertical spring whose stiffness constant is 9N/m. The block is released at the position where the spring is unextended. What is the maximum extension of the spring? How long does it take the block to reach the lowest point?
Homework Equations...
Homework Statement
[/B]
Hello!
I have this question which I don't quite know how to solve...
ABC is an equilateral triangle - the length of its sides equal to (a).
DE is parallel to BC
1. What length should DE be to achieve the largest possible area of triangle BDE?
2. What length should DE...
Ive been given a question which I'm stuck on and cannot answer. I've only been able to calculate the maximum allowable working stress and other then that I am stuck on how to answer the following question:
A specimen of the same material that was used in the above test (mild steel), had a cross...
I'm just doing some geometry and I can't remember how to find the maximum values of two variables in the same equation. Like, if you differentiate the equation partially for one, then again from the beginning partially for the other and add them together or something.
The equation is something...
Homework Statement
A certain type of concrete has a tensile breaking stress of 3.1 MN/m^2, a compressive breaking stress of 37.7 MN/m^2 and a shear breaking stress of 9.4 MN/m^2. A circular pillar of this concrete has a radius of 0.6 m. What is the maximum load it can support assuming that it...
Homework Statement
You wish to use an LED (D1) which provides essentially zero resistance and is rated to accept either a maximum of 75 mW of power or 30 mA of current. In the following two circuits, what range values for resistor R1 will be acceptable in each case if the voltage provided by V1...
Homework Statement
The whole problem is in picture, but simply it says to find the max velocity of rocket, with those given units.
The whole problem is worked out with pounds, but when I try to do it for meter and Newtons I get like 50 times bigger answer.
The units :
Total Impulse of motor...
Homework Statement
Maximum no. of comparisons required to merge two sorted files of length 'm' and 'n' is..
Homework EquationsThe Attempt at a Solution
I think m+n-1
In my physics book, one of the basic quick quizzes checkpoints asks what happens to the central peak in a diffraction envelope when you decrease the wavelength of light (from 650 nm to 450 nm, for reference).
My understanding is that the width of the peak would decrease, while the number of...
Hello,
First, please understand that I'm lacking fundamentals in physics and engineering.
I'm trying to find the maximum pressure a submarine hull can resist. For the sake of simplicity I'm just considering a tube closed with magical caps that keep a different pressure inside and outside...
Homework Statement
A pendulum hung by a string that is 90m (simplicity's sake) can come a maximum of 72m leftward or right ward. Where does it feel it's maximum momentum?
m=meters M=mass
Homework Equations
PE=mgh
KE=.5(M)(v)^2
Mv= momentum
The Attempt at a Solution
My question is: will a...
Hello, I want to ask the explanation for this basic problem.
So I have 2 resistors in parallel(X and Y) and I want to maximize the power going through the resistor X, by choosing the resistance.
This can be achieved only by choosing the same resistance for X, than Y has.
Why is this so? I can...
My book says 'Maximum work can be obtained only from thermodynamically reversible processes,' but why is it so? What is the cause?
Actually to me the definition of reversible process is confusing. It says that at each step during the process, equilibrium is maintained. But, let's say,we have to...
I read somewhere (article, messageboard, i can't find it anymore) that motherboard bus speeds are limited because if the frequency gets too high then the signal will disappear. I guess I understood it to mean that the bus wire will become like and antenna if the frequency is too high.
They...
Homework Statement
A coating of n1 = 1.33 material is to be added to n2 = 1.50 glass, in order to make it "irridescent."
a) What is the thinnest layer of material which will have a reflection maximum for normal-incidence light at BOTH 400 and 600 nm (vacuum) wavelength?
b) This thickness will...
Homework Statement
y(x,t) = (9.00cm)sin((5Πcm-1)x + (3Π rad/s)t - Π/8)
There are 11 parts, and I have answered the first 10 (they include velocity of a wave, amplitude, all that good stuff), but I haven't seen anything in lecture or in the textbook that mention finding maximum vibration speed...
http://puu.sh/dc1YU/fa1e0f3a6e.png
Hey so if we have a trajectory like this, where would it be maximum speed?
From what I understand, at the midpoint, v = 0 right? So would the maximum speed be in between the bottom (initial) and the centre of the trajectory (peak), represented by B in this...
Homework Statement
A current loops is oriented in three different positions relative to a uniform magnetic field. In position 1, the plane of the loop is perpendicular to the field lines. In position 2 and 3, the plane of the loop is parallel to the field as shown. The torque on the loop is...
if one string can hold a block of 100kg, how much weight can two strings connecting the ceiling and one single point hold a block?? is it 200 kg? if yes, then what about one string connecting the ceiling and one single point of the block two times, three times or more? [im sorry if the grammar...
Problem:
I do not know how to approach this problem. For a beam which has two reactions, the shear stress is equivalent to the reaction.
I suppose that the stress is calculated using moment some how. But how?
For seeing if the beam is allowable stress design compliant, you can use the...