Homework Statement
A point source in water provides 10 W of heat for 10 seconds, and is then shut off. The surrounding water has a temperature of 20 °C. Provide the temperature profile as a function of distance r and time t.
Homework Equations
The Attempt at a Solution
If it...
I did draw the free body diagram, but I have a lot of trouble understanding the concept of moment.
There should be a reaction moment at the wall even without P I just realized; this reaction moment has to cancel PL. But I find it really hard to see what I need to do with the moment M.
Would...
Homework Statement
A cantilever beam (prismatic, rectangular cross section) is loaded at the tip by a force
P and at half its length L by a moment M.
a. Calculate the reaction force and moment.
b. Draw the shear force and bending moment diagrams
Homework Equations
∑F=0; ∑M=0
The...
There is no angle given, so you shouldn't assume any angle. You can calculate vx and vy without using the angle. If you want to know the angle afterwards, you can calculate it from vx and vy.
Yes, you indeed made a wrong assumption on the angle.
If you take a good look at the values given, you should be able to calculate vx without much trouble.
Then you only need to calculate vy.
I am not sure how to explain it properly, but the third point charge can't really affect itself, can it. So you just calculate the electric field at that point as if it wasn't there.
Your method for a is correct, you just forgot to write the 1/r².
For question b, you just need to think about what happens to the charges. What changes when you go from an insulated spring to a conducting one?
You know how to calculate the force between two charges. You can just calculate the force that act on the last charge from the first one, and then the force it feels from the second one. Then you can just add up the two forces. Just make sure you know you're adding up vectors.
s should be 1/2, sorry for that. Thanks for pointing me in the right direction, I'm a lot closer to the answer now (I think so, atleast).
If I am correct, the 'spin-angle functions' would give me the number of bases vector, and thus the dimension of the Hilbert-space.
This is dependent on...
Homework Statement
Consider the states with the quantum numbers n = l = 1 and s = 1/2
Let
J = L + S
What is the dimension of the Hilbert space to describe all states with these
quantum numbers?
Homework Equations
The Attempt at a Solution
I believe the dimension of the Hilbert...
Your f(x-at), set:
y=f(u)
u=x-at
Chain rule: dy/dx=dy/du*du/dx
dy/dx=f'(u)*1
This is how you can differentiate your function, same goes for differentiating to t.
If all goes well, the f'(u) should cancel out.
Also, you have the wrong wave equation there; both differentials are with...
Homework Statement
I have a hollow conducting sphere with a charge on it, and I'm looking at the static situation. Where are the charges located?
Homework Equations
Gauss' Law
The Attempt at a Solution
A static situation, so no electric field inside the sphere, or charges would move...