Homework Statement
An object is placed 60 cm from a thick double convex lens, with faces of radii of curvature 20 cm and 30 cm, with thickness of 2 cm, and index of refraction is 1.5. Find the position of the image...
4.
a) A certain string has a linear mass density of 0.25 kg/m and is stretched with a tension of 25 N. One end is given a sinusoidal motion with frequency 5 Hz and amplitude 0.01m. At time t=0, the end has zero displacement and is moving in the positive y-direction. Find the wave speed...
I just started studying this stuff but on a couple occasions my answer was a different sign than the teacher's answer key, so I used the wrong function. This is what confuses me, how to know which to use in order to get the right sign. In the question, an end of a string is given sinusoidal...
Hi, I'm looking through my teacher's notes and he says that a wave function for a sinusoidal wave can be written: y = A sin (ω t – k x) or y = A sin (k x - ω t)
The textbook gives it in the second form. I think that using one over the other gives the same answer but in the opposite sign. I...
If V = kc (integral) (x)dx/(d+x)
then shouldn't E = -dV/dx where dV/dx just equals (d/dx)(kc (integral) (x)dx/(d+x)) which equals (kc(x))/(d+x)
so E = -(kc)(1/2) = -8.99 x 10^3 N/C ?
Yes it is a rather badly worded problem...
But yes, from my discussion with other students, we placed the rod's extreme left end at the origin. I wish I could show my work but I have it on paper and this is the last thing I have not done for this 5 problem assignment. I will have to pick one...
I've just spent time with another student with this problem and we're really lost because we've got 4 different answers from different sources and not one of them are the same. We've gotten 8.99 x 10^3 N/C, -3.47 x 10^3, -1.45 x 10^4 N/C, and 4.225 x 10^4 N/C from the above poster. Can anyone...
I've done all my work on paper and I ended up with E(x) = -kc[ln(L-x) + x/(L-x) -1 -ln|x|] where x = -d where d is 1m. It's been a couple days but I plugged in my numbers and got 1.45 x 10^4 N/C. But this is a positive answer, shouldn't the electric field be to the left/negative?
Homework Statement
The plastic rod of the length L=1 m has a non-uniform charge density λ=cx where positive constant c =2x10^-6 [some unit]. What unit c has to have? Find the electric potential at the point on the x axis 1 m to the left from the left end of the rod. Find the electric field at...
Homework Statement
The plastic rod of the length L=1 m has a non-uniform charge density λ=cx
where positive constant c =2x10^-6 [some unit]. What unit c has to have? Find the electric
potential at the point on the x axis 1 m to the left from the left end of the rod. Find the
electric...
Hi, if you have the book: Physics for Scientists and Engineers 8E, Serway Jewett
On page 675 (Chapter 23), Example 23.8 there is a step taken during the integration I don't understand:
How do you go from "2r dr" in the numerator to d(r^2)? If there is info or link to the property of...
I found it online:
http://www.cramster.com/answers-sep-10/physics/blocks-masses-m1-m2-nbsptwo-blocks-masses-m1-m2-table_950775.aspx
The answer key gives:
b) F, c) F - P, d) P, e) m1: F - P = m1a; m2: P = m2a
I want to add that obviously in the book the coefficients are labeled "mu"1 and 2
Homework Statement
In Physics for Scientists and Engineers Volume 1 Eighth Edition (Serway, Jewett)
Number 55. in Chapter 5, I checked the answer key and would like to know why they don't consider the forces of friction in a), b), c), d), and e)? This confuses me. Thank you.
Homework...
Ok that makes sense. If the ball were coming from the right side would we add mvL instead, because the momentum being added to the system is in the same direction of its initial angular momentum?
Homework Statement
http://tycho.physics.wisc.edu/courses/phys201/fall06/Discussion/Disc14Solution.pdf [Broken]
problem 38, part b)
Homework Equations
I final w final = I initial w initial
The Attempt at a Solution
I understand that the snowball is introducing a net torque and I know that...
Homework Statement
Problem 7.29:
http://cas.umkc.edu/physics/wrobel/phy240/Homework%20%205.pdf
Homework Equations
dr= R d(theta)
The Attempt at a Solution
I don't understand how to get R d(theta) = dr from the last part of the question, any explanation about how it works is...
Wow ok thank you for that information about cubic degrees and their relation to constant acceleration, I will stick to my derivative answer but I was just curious as to other types of solutions because I know that many students in the class have not completed their differential calculus seeing...
Well I plugged in my new values for initial position and got 46.9 N but I don't think that's the right answer.
19 m = -1 m + 0 + (1/2)ax(t^2)
ax = 10 m/s^2
26 m = 2 m + 0 + (1/2)ay(t^2)
ay = 12 m/s^2
so Fx = (3.00 kg)(10 m/s^2) = 30 N
and Fy = (3.00 kg)(12 m/s^2) = 36 N
Ft =...
I guess I assumed that the initial velocity was zero because plugging t=0 into the derivative of the equations would get you 0 from the velocities? I used differentiation to come to that conclusion.
Oh wait a second, I guess the initial positions wouldn't be zero since plugging t = 0 would...
Homework Statement
Hi all, I'm trying to understand why my second way of solving this problem doesn't work:
A 3.00kg object is moving in a plane, with its x and y coordinates given by x= 5t^2–1 and y=3t^3 + 2, where x and y are in meters and t is in seconds. Find the magnitude of the net...
Wow that is very very interesting. Unfortunately this is one of my physics lab questions and the physics lab we are taking is completely separate from the physics course itself so the topics covered by our professor are not related strongly to the labs. For example I have no idea about the...
I calculated the volume of the copper based on its density and air weight:
V = 180 gm/(8.93gm/cm^3) = 20.2 cm^3
Used that volume and the submerged weight:
d = 162gm/20.2 cm^3 = 8.02 gm/cm^3
I don't think I did it right because I'm not familiar with the physics of the situation but I'm trying...
1. A piece of copper whose density is 8.93 gm/cm^3 weighs 180 gm in air and 162 gm when submerged in a certain liquid. What is the density of the liquid?
2. d = m/v
3. I wasn't sure how to compute this but I calculated the volume of the copper based on its density and air weight...