Homework Statement
A wire is used to keep two uniform posts from falling, as in the figure. The wire is
5.00 m long, and has a mass of 0.732 kg. The posts are identical and are uniform in cross
section, with a mass of 25.0 kg each.
a. Find the tension in the wire (assume the wire is...
Homework Statement
See attachment please.
Homework Equations
The definition for Young's modulus. Newtons second law. Pythagoras' formula.
The Attempt at a Solution
I know from physics 1 that I have to apply F=ma to the point where two "triangles" meet. The phrase "the...
Why don't I get shocks on neutral wire?
In my textbook the AC current is defined to be one which changes its direction periodically.
So according to the text both the wires of the AC supply should give you shock, but I felt the real shock when I observed that the neutral wiring didn't shook...
Biot-Savart Law-- magnetic field produced by single wire.
Homework Statement
A wire of length L, carrying current I lies along the x-axis as shown in the picture. A
point P is located a distance 2L below the right end of the wire, as shown.
a) Determine the direction of the contribution dB to...
Hi, I'm doing some revision and I'm having a problem with the following:
Conductivity of gold is 4.1*10^-8 , what is the electric field along the wire? The current is 13.2A and the radius is 3.8mm
I've used 1/conductivity to find resistivity of (2.4*10^-8) and used this along with area to...
So let's say I have a current, going into the page (that is, -\hat{k}). And now let's say you're trying to figure out the magnitude and direction of the magnetic field 0.0346 m away from it, in the SW direction (45 degrees).
How would you calculate the answer in terms of unit vectors \hat{i}...
I'm self-studying an introductory book on mathematical methods and models and came across the following problem:
1. A bead of mass m is threaded onto a frictionless horizontal wire. The bead is attached to a model spring of stiffness k and natural length l0, whose other end is fixed to a...
Hi,
Homework Statement
A square frame with a thin crust/layer of liquid with surface tension γ is given. Into the plane of the frame an elastic wire of circular shape with radius r_0 is inserted. The thin crust/layer of liquid is then burst (by pricking) and as a result of the force of...
Homework Statement
What is the magnitude of the force per unit length on a long wire of charge density λ from a wire that carries a current of 3 A and is a distance of 3 m away?
A)μλ/2 B)μλ/6 C)3μλ/2 D)μλ/3 E)0
The Attempt at a Solution
F=BIL→ (F/L)=BI →(F/L)=μI1I2L/2∏R
I don't...
Homework Statement
A portion of Nichrome wire of radius 2.50 mm is to be used
in winding a heating coil. If the coil must draw a current of
9.25 A when a voltage of 120 V is applied across its ends,
find (a) the required resistance of the coil and (b) the
length of wire you must use to...
Hi,
I would like to know if it is possible to move a steel wire against frictional forces using a magnet. What would be the approach of calculating the force acting on that thin wire. I would know the dimensions of the wire and the dimensions of the magnet. What other values should I find...
What model correctly predicts the sensitivity of a resisitive wire straing gage to applied strain?
This question is motivated by an an old pamphlet found in a used book store, "Theory Of Strain Gage Flight Test Instrumentation" by Eugene Frank, 27 May 1946.
The gage factor of a strain gage...
Cylinders for Piston Engines go through a final process of grinding and honing to achieve a surface finish that is fine enough to prevent as much friction as possible yet rough enough for holding engine oil for lubrication between the Cylinder and the Piston.
The required Surface Finish is...
Homework Statement
The electric field in a 1.2mm x 1.2mm square aluminum wire is 2.0×10^-2 V/m What is the current in the wire? I = ?A
Homework Equations
E = V/length
R = ρL / A
I = V/R = V*A/ ρ*L
The Attempt at a Solution
Electrical field strength E = V / length = 2 x 10^-2 V/m...
Homework Statement
A wire is fixed at both ends vibrating fundamentally. For what value of x (x position on the wire, with 0 being one edge and L being the other) is the potential energy per unit length has the maximum value?
Known: Length of wire (L), Tension in wire (T), Mass of wire (m)...
Hi I have a cable that is fixed at 2 points, and I would like to model the curve that it bends as the two points move together and further away.
In one scenario, the cable is fixed at both ends (one above the other) like a "C".
In the other scenario, both ends are also fixed in clamps, but...
Homework Statement
I'm doing a lab report and the last question is, how would your measurements (currents and voltages across each resistor) be affected if the resistance of the wires is 0.01 Ω and the internal resistance of the voltmeter is 10 MΩ?
Homework Equations
The Attempt at a...
Hi.
I am wondering how I can diagnose a winding and find out whether it is damaged. Windings like for solenoids or electromagnets operating on 12VDC.
Or even for 12V motors.
I want to know how I can detect a turn to turn shorted winding. Does an electromagnet lose magnetic power and...
Homework Statement
Calculate the electric field at a point 2.79 cm perpendicular to the midpoint of a 2.02 m long thin wire carrying a total charge of 5.04 uC.
You could integrate BUT if the wire is very long compared to the distance from the wire to where you are calculating the electric...
Homework Statement
Two wires, each having a weight per unit length of 10–4 N/m, are strung parallel, one 0.3 m above the other. If the wires carry the current of same magnitude, how great must the current in each wire be for the magnetic field due to the lower conductor to balance the weight...
There is a street lamp that weighs 150N. The two wires that are attached to it form at 120°. What is the tension on the wires?
So i drew a diagram. Since the force of gravity acting on the lamp is 150N down, there must be an equal opposite force acting at 150N up.
Then I drew a right...
Hi, I'm working on an idea and i need some guidance
say i have a wire loop of a single wire (not solenoid) the area of the loop is about 1-2 cm^2
now say i change the area of the loop slightly by about 0.1%-0.01%
could i measure with today's electronics this slight change of L
thanks in...
Homework Statement
A 0.60 m long circular tungsten wire with a radius of 0.05 m is connected to a DC power source resulting in a current of 0.65 A in the wire. Calculate the magnitude of the electric to magnetic field ratio at the surface of the wire. The resistivity of tungsten is 5.6 · 10-8...
Homework Statement
We have a bead sliding on a frictionless hoop oriented vertically. First the hoop rotates about its center with rotation axis perpendicular to its plane.
Second, the hoop rotates about a vertical axis as well.
In both of these cases, are the constraints holonomic or...
Homework Statement
Pulley with Friction
A spool of thin wire pivots on a shaft, and there is friction. The wire is pulled by a hanging mass M of 1.30 kg. After falling a distance D= 1.7 m starting from rest, the mass has a speed of 0.065 m/s. Calculate the energy lost to friction during that...
Homework Statement
A wire carrying a 31.0 A current bends through a right angle. Consider two 2.00 mm segments of wire, each 3.00 cm from the bend. A figure has been included.
Part A) Find the magnitude of the magnetic field these two segments produce at point P, which is midway between...
Homework Statement
In the circuit shown, two thick copper wires connect a 1.5 V battery to a Nichrome wire. Each copper wire has radius R = 7 mm and is L = 18 cm long. Copper has 8.4 × 10^28 mobile electrons per cubic meter and an electron mobility of 4.4×10^−3 (m/s)/(V/m). The Nichrome wire...
Semicircular Wire
A positively charged wire is bent into a semicircle of radius R, as shown in Figure 2.15.4.
The total charge on the semicircle is Q. However, the charge per unit length along the
semicircle is non-uniform and given by
λ = λo θ cos .
(a)...
Homework Statement
A flat object shown here consists of a circle and square made of heavy, uniform wire and welded together at the corners of the square. The mass of the circle is M. The mass of the square is m and its side has a length d. To find the objects moment of inertia about Axis A...
Homework Statement
In lab, we were instructed to create a circuit that uses nichrome wires and identical bulbs to measure the obstacle caused by an object. To do this, we slid the alligator clip along the nichrome wire until the 2 bulbs in parallel are the same brightness. The object that we...
My first-year engineering group is designing an automatic shut off oven system. We will integrate smoke detector systems inside the oven. Details about that don't matter.
Smoke detectors work on a trip wire type alarm. Alpha particles are emitted from a small source of Americium, the alpha...
Homework Statement
A long wire lying along the x-axis carries a current of 2.60 A in the +x direction. There is a uniform magnetic field present, given by B=0.003i + 0.004j + 0.002k, where i, j, k are the unit vectors along the cartesian coordinate axes') in units of Tesla. Calculate the...
A circus performer of weight W is walking along a "high wire" as shown. Then tension in the wire is: A) approximately W, B) approximately w/2 C) mush less than W, D) much more than W, E) depends on weather he stands on one or two feet
Description of picture: Their are two polls in the ground. A...
As far as I understand, the wires in classical Newtonian mechanics are inextensible, unbreakable and so forth. The part that confuses me is that sometimes there are two tensions in the wire, or rather the tension is in both senses. Is that because there are opposing forces acting on the two...
Homework Statement
What diameter must a copper wire have if its resistance is to be the same as that of an equal length of aluminum wire with diameter 3.94mm?
Give your answer in mmHomework Equations
R = ρL/A
where A is the cross sectional area, L is the length and ρ resistance of the...
So I'm just supposed to calculate the tension in the wire (see attachment) and get to the formula shown. What I've done so far is to draw free body diagrams of all the boxes, and then I've just tried to set up some equations and manipulate them.
However, I can't seem to end up with the...
Homework Statement
A long horizontal wire carries a current of 48 A. A second wire, made of 3.0 mm diameter copper wire and parallel to the first, is kept in suspension magnetically 15 cm below. Determine the magnitude of the current in the lower wire.
Homework Equations
μI / 2∏r
The...
Homework Statement
I have a long straight wire which is slightly deformed into sinusoid shape. How does the magnetic field change with deformation? Can you express the magnetic field change linearly with sinusoid amplitude?Homework Equations
parametrized sinuosid equation
x = t
y = a*sin(t)...
Homework Statement
The center of the spherical metal ball of
radius R, carrying a negative charge -Q, is
located a distance r from the center of a short,
thin, neutral copper wire of length L. The
induced charges at the two ends of the wire is
±q. Determine the polarizability of the...
We just went over Faraday's law in class and our teacher stressed how a changing flux is needed to induce an emf in some coil/loop/wire.
I was just wondering then, how is an emf induced in a straight conducting wire moving at a constant velocity in a constant magnetic field? It seems as if...
Homework Statement
In the picture.Homework Equations
Right/left hand rule? The Attempt at a Solution
I have tried applying the right hand rule to this situation, but they only give me the current and nothing else, so i can't determine the direction of the magnetic field in the point P.
Off the Wikipedia:
"...in a copper wire of cross-section 0.5 mm2, carrying a current of 5 A, the drift velocity of the electrons is on the order of a millimetre per second."
Suppose we have a setup with a very very light wire which can transmit very very high currents. Once the current is...
Homework Statement
A 3 m long copper wire that has a diameter of 6 mm is connected to a 9 V battery.
a) What is the current through the wire?
b) If wire a was connected to a battery for 1 second, how much energy would the wire dissipate?
Homework Equations
A = \pir^{2}
R = \rho\frac{L}{A}
i =...
I'm trying to build a ball and beam balance control system. I was thinking of using a metallic ball and two wires to make a linear potentiometer to give the ball's position. I'm not sure what to use as the resistive wire. Most wire I find doesn't seem to provide a sizable amount of resistance. I...
I knew the one inch wire rope was under severe strain, that's why I was watching it when it parted (broke). First, a few of the individual steel wires broke with some small time interval between each break. Then more wires broke at a faster rate until the remainder broke all at once. It was...
I'm trying to find a silver chain that can be used for a small bead with a small hole. Obviously, the chain needs to be thin enough to fit through the hole, but I can't measure the hole inside the bead by hand.
I found a chain that is 0.9mm in diameter, but I'm not sure the bead will fit. So...
Homework Statement
Which wire will experience the biggest force?
a. 1
b. 2
c. 3
d. all wires experience the same force
e. can't be determined without additional information
Homework Equations
F = BIL sin θ
The Attempt at a Solution
Can the above formula be applied to a...
Homework Statement
Write code to calculate the input impedance on a thin wire antenna using the below form of Pocklington's integral equation. Use Method of moments.
Use a pulse as the basis function, point matching and delta-gap generator as the 'source'.
Assume the wire is broken up into 7...