When referring to the absolute magnitude ,for example, in the B filter of a distant galaxy(considered point source) what are we talking about? Are we talking about the observed redshifted flux density(luminosity density) hypothetically seen from 10 pc away (1) ; or are we talking about the...
Homework Statement
Consider the electric dipole seen in the notes. (a) Using integration, derive an expression for the magnitude of the electric field produced by the dipole at any point along the x-axis.
Electric Dipole: http://labman.phys.utk.edu/phys136/modules/m5/images/electr5.gif...
Homework Statement
Calculate the magnitude of the electric field at the center of a square 42.5cm on a side if one corner is occupied by a −38.2μC charge and the other three are occupied by −27.0μC charges.
Homework EquationsThe Attempt at a Solution
E=k(q/r^2) the direction of the electric...
Homework Statement
Calculate the magnitude of the electric field at the center of a square 42.5cm on a side if one corner is occupied by a −38.2μC charge and the other three are occupied by −26.9μC charges. (This part done)
Choose the correct direction of the electric field at the center of...
Homework Statement
An object is moving in the xy-plane according to the equations x(t) = 3sin(3t) and y(t) = 4cos(3t). What is the maximum magnitude of the particle's acceleration?
1) 5 m/s22) 15 m/s23) 30 m/s24) 36 m/s2 [the accepted answer]5) 45 m/s2
Homework Equations
x(t) =...
Homework Statement
Homework Equations
The Attempt at a Solution
https://scontent-lhr3-1.xx.fbcdn.net/v/t34.0-12/13140955_10156888508510486_863100825_n.jpg?oh=3f13a038f3dc053c7a10858aa62f6fc0&oe=57318819...
https://scontent-lhr3-1.xx.fbcdn.net/v/t34.0-12/13181084_10156883800920486_1357045350_n.jpg?oh=a39d7777f01c4aa06301c4f3d740de1e&oe=57301DBC
Hi
I am currently studying design engineering and my lecturer has left just before an exam. I really don't know how to find the magnitude and direction of...
Homework Statement
Hey everyone I have a physics e&m question: [/B]
http://blob:https%3A//www.physicsforums.com/aa779f37-be23-43d7-a888-d70263a3854b
Homework EquationsThe Attempt at a Solution
I took the derivative to find the magnitude of the induced voltage. (do I need to add a constant...
Hello,
I am wondering how is the magnitude of the time dilation in a gravity field related to the time dilation we know from special relativity. How does the dilation caused by just being in the field compare to the dilation you'd have from your velocity if you fell into the gravity field from...
I'm sure this is a simple concept but i just can't wrap my brain around it, the question is:
a) Express the following vectors in terms of x-y coordinates:
i)Vector V with direction π/6 and magnitude 4√3.
ii) Vector W with direction 5π/4 and magnitude 4√2.
b) Express the vector v + w in terms...
Homework Statement
Copper and aluminum are being considered for a high‐voltage transmission line that must carry a current of 51.4 A. The resistance per unit length is to be 0.176 Ω/km. Compute the magnitude of the current density for an aluminum cable.
Homework Equations
R\quad =\quad \frac {...
Homework Statement
A beam contains 3.95×108 doubly charged positive ions per cubic centimeter, all of which are moving north with a speed of 1.64×105 m/s. What is the magnitude of the current density?
Homework Equations
J = nev
n = electron density
e = electron charge
v = drift velocity
The...
Limited information at this time:
http://www.9news.com.au/world/2016/04/03/18/48/preliminary-magnitude-7-point-2-earthquake-strikes-off-vanuatu#RLUVoLYwGDV21je9.99#9News
http://www.stuff.co.nz/world/78508265/72-quake-has-struck-off-vanuatu
Homework Statement
A circular rod has a radius of curvature R = 8.11 cm, and a uniformly distributed positive charge Q = 6.25 pC and subtends an angle theta = 2.40 rad. What is the magnitude of the electric field that Q produces at the center of curvature?
Homework Equations
E = kQ/r^2
6.25 pC...
Homework Statement
"Assume that a train is traveling at 65 cm/s, and the track has radius 20cm. What is the magnitude of the train's average acceleration as the train goes from the tree marked A to the next tree B, located exactly 1/4 of the way around the track from tree A? [Hint: This...
Homework Statement
The boundary shown is that of a uniform magnetic field directed in the positive z direction. An electron enters the magnetic field with a velocity pointing along the x-axis and exits 0.63 μs later at point A. What is the magnitude of the magnetic field?
Homework Equations...
So to find the x values of the stationary points on the curve:
f(x)=x3+3x2
you make f '(x)=0
so:
3x2+6x=0
x=0 or x=-2
Then to find which of these points are maximum or minimum you do f ''(0) and f ''(-2)
so:
6(0)+6=6
6(-2)+6=-6
so the maximum has an x value of -2 and the minimum has an x value...
Homework Statement
When doing force problems, you're sometimes asked to solve for the magnitude and direction of a given force acting on an object given the mass of the object, its accelleration, and the other forces acting on it. However, the force that you need to solve for could be...
Hello Everyone
I'm new to this community so I hope that I have posted this question to the correct forum. If not, please advise on the best forum for my question.
Recently, I have been trying to find a reliable formula to calculate a specific telescope's limiting magnitude while factoring...
Homework Statement
An electron accelerated from rest through a voltage of 420 V enters a region of constant magnetic field. If the electron follows a circular path with a radius of 29 cm, what is the magnitude of the magnetic field?
Homework Equations
r=mv/lqlB
K=VQ
Conservation of Energy...
Hi,
I am curious as to whether there is a relationship between field lines and magnitude of charge. For instance, is the sketch for the electric field of a +1.0 micro coulomb charge the same as the sketch for a +2.0 micro coulomb charge?
Thanks. All help is very much appreciated!
Homework Statement
13. Find the magnitude and direction of the electric field at P due to the two charges shown.
Homework EquationsThe Attempt at a Solution
I have attached both the question, which involves a diagram, as well as my attempt at the answer below. My first question is regarding...
Homework Statement
The electric potential difference across a neuron cell membrane is 0.070 V. The thickness of the membrane is 5.0 x 10-9 m.
a) Find the magnitude of the electric field across the membrane. Describe any assumptions you are making.
Homework Equations
ε = V/r
The Attempt at...
A car travels around a circular track with a radius of r=250m. When it is at point A then VA=5m/s which increases at a rate of a=(0.06t)m/s2. Determine the magnitude of its velocity and its acceleration when it is 1/3 around the track. My distance in this situation is obviously 524m.
Can anyone...
Homework Statement
A long coaxial cable consists of an inner cylindrical conductor with radius a and an outer coaxial cylinder with inner radius band outer radius c. The outer cylinder is mounted on insulating supports and has no net charge. The inner cylinder has a uniform positive charge per...
Homework Statement
A 500 kg ox runs and speeds up by 3 m/s2, but is held back by a 120 kg plow that is attached to its back. Assuming the coefficient of static friction between the horse's hooves and the soil is 0.73, what is the magnitude of the static friction force the soil exerts on the...
Homework Statement
You start at a distance r from a point charge. The electric potential is 4500V at that point, and the electric field is 2.3x105N/C. a) What is r? b) What is the electric potential and magnitude of the electric field at a distance of r/4?Homework Equations
v= kq/r E=kq/r^2...
Homework Statement
A small plastic ball of mass 7.51 × 10-3 kg and charge +0.123http://edugen.wileyplus.com/edugen/courses/crs6407/art/qb/qu/c18/lower_mu.gifC is suspended from an insulating thread and hangs between the plates of a capacitor (see the drawing). The ball is in equilibrium, with...
Homework Statement
Calculate the magnitude and coordinate angles of the resultant couple moment, caused by the forces.
Homework Equations
M= r x F
The Attempt at a Solution
M3= -0.2* 80k= -16k
M2= 0.2* 120i= 24i
M1= -0.2*100j= -20j
M4= r x F= ?
I just can't seem to be able to expres r into a...
Homework Statement
(This is a long problem but I think the question is not hard.)
Determining the star density from star counts is tough, but estimating counts from a density law is simpler. In practice, this method of fit-ting observed number counts to an assumed density law is becoming a...
Homework Statement
A closed surface with dimensions a = b = 0.302m and c=0.604m is located as in the figure.
The electric field throughout the region is nonuniform and defined by E⃗ = (α+βx2)ˆı where x is in meters,α=4N/C, andβ=4N/(C·m2).?
What is the magnitude of the net charge enclosed by the...
Homework Statement
Vector A⃗ has a magnitude of 20m and makes an angle of 30∘ above the positive x axis. Vector B⃗ has a magnitude of15m and is oriented 60∘ to the left of the y axis.
Find the magnitude of A⃗ −B⃗ .
Find the direction of A⃗ −B⃗ .
Homework Equations
sin 150 = sin 30 = 0.5
cos...
Hello,
I'm working on a hypothetical situation involving a planetary body orbiting a black hole (similar to the scenario in Interstellar, but for different reasons), trying to balance tidal forces with orbital distance and time dilation.
First, I'm interested in the effect of gravitational...
Homework Statement
m=25 kg, F1=88N[E55N],F2=54N[E], mu (coefficient of friction) = 0.350
Homework Equations
FNet=F1+f2-Ff
The Attempt at a Solution
88cos55 + 54=104.47, 88sin55+0=72.1. dheta=tan inverse (72.1/104.47)=34.6 degrees, what direction is Ff is my question and I would appreciate a...
Homework Statement
[/B]
A thin light string is wrapped around a solid uniform disk of mass M and radius r, mounted as shown. The loose end of the string is attached to the axle of a solid uniform disc of mass m and the same radius r which can roll without slipping down an inclined plane that...
When a nucleus gamma decays, the gamma has its intrinsic spin of ##1\hbar##, but it can also carry away a significant amount of angular momentum in addition to that. Quadrupole radiation is very common, and in exceptional cases you can even get gammas with 5 or ##10\hbar##.
Now suppose I do the...
1. The problem statement, all variables and given/known dat
Show that if you have a signal f and noise σf for a stellar flux measurement, then the uncertainty on the observed magnitude is given by
σm = 1.0875 x σf / f
Homework Equations
(you should use the fact that when ε<<1 then log(1±ε) ≈...
Homework Statement
A coaxial cable consists of an inner cylindrical conductor of radius R1 = 0.040 m on the axis of an outer hollow cylindrical conductor of inner radius R2 = 0.080 m and outer radius R3 = 0.090 m. The inner conductor carries current I1 = 4.4 A in one direction, and the outer...
Homework Statement
Two long wires (in cross section) that each carry a current ##i## directly out of the page. What is the magnitude of the field at point ##P##, which lies on the perpendicular bisector to the wires?
Homework Equations
##B_{wire}=\frac{\mu_0 i}{2\pi r}##
The Attempt at a...
Homework Statement
can someone tell me why the acceleration in n direction is 18ms^-2 ? i only understand that the centripetal acceleration = 18ms^-2Homework EquationsThe Attempt at a Solution
I am stuck on a problem regarding the minimum magnitude of an astronomical object that can be handled by a given telescope+spectroscope combination. The telescope aperture (D_T) is 2 m wide, the exit beam (D1) is 3 cm wide. The slit width (s) is 10 micrometers. The wavelength of interest is 450...
Homework Statement
A charged body, moving with a velocity of 8.0 * 104m/s at an angle of 30.0° with respect to a magnetic field of strength 5.6 * 10-5 T, experiences a force of 2.0 * 10-4N.
What is the magnitude of the charge?
Homework EquationsThe Attempt at a Solution
I have no idea where to...
Homework Statement
A system consists of a bicycle and a cyclist traveling at a constant velocity along a horizontal road.
The total resistive force acting on the system in 4.0N and its speed is 8.0 m/s. Calculate the useful power output of the cyclist.
The cyclist stops pedalling and the...
1. A solid disk of radius R and mass M is initially spinning clockwise with an angular velocity magnitude ω. It is placed against a flat, horizontal surface with a coefficient of kinetic friction of μ.
Find the frictional torque magnitude on the disk, and how long it will take the disk to come...
Homework Statement
Question: [/B]A 600-kg car traveling at 30.0 m/s is going around a curve having a radius of 120 m that is banked at an angle of 25.0°. The coefficient of static friction between the car's tires and the road is 0.300. What is the magnitude of the force exerted by friction on...
Homework Statement
A gorilla is hanging from 2 vines, each with an angle of 30° from perpendicular.
Find the Magnitude of the force of tension in each vine.
Object mass is 3.10 x 10² kg
I have made an attempt at this. I have attached my handwritten notes.
Lots of feedback please.
Thank you in...
Homework Statement
See picture.
Homework EquationsThe Attempt at a Solution
I tried drawing a parallelogram, but it didn't help, so I'm stuck. I'd need an idea in the right direction, if possible.