A block with a speaker bolted to it is connected to a spring having spring constant k= 20.0 N/m as in Figure P17.40. The total mass of the block and speaker is 5.00 kg, and the amplitude of this unit's motion is 0.500 m. (a) If the speaker emits sound waves of frequency 440 Hz, determine the...
I know that T = RC
I've tried different combinations of R (not really sure what Req to take) but none of them worked. Any one can show me the right way ?
But where does that come in the formula
P= Stefan-boltzmann constant X emessivity X surface area X (T environment^4 - T of the cylinder^4)
Edit: I reread the chapter in my book and I found a small part that describes when its positive and when it's negative.
But there isn't anything in the...
oh I apologize, I'll avoid doing that in the future.
Could you elaborate on what you said about the convention?
All I know that the transfer rate is:
P= Stefan-boltzmann constant X emessivity X surface area X (T environment^4 - T of the cylinder^4
Where does a convention come in ?
Oh sorry about that, I didn't notice it. So there isn't something I missed ? This is frustrating I've been over it a million times and I always get the same answer.
I asked a friend of mine to get the person he did for him to do mine. He got -1.72 and it is correct. Why is that ?
@Mapes
I copied the S-B constant from my book and I verified my area with an online area calculator.
P2/P1 = 2.75 (I got it right)
@D H
1.72W
I didn't mention the units because they are clearly stated in the screen shot I attached.
we use wiley plus and when i submited my answer it says it's wrong (there's a 3% tolerance). But I think you can agree that there is nothing wrong with my answer - I calculated it multiple times before posting here.
oh sorry. I was planning on attaching an excel file with calculations. Any way here is what I did. Yes I converted from Celsius to kelvin.
P= 5.6704 x10^08 X 0.81 X 0.009814 (surface area) X (338.15^4 - 310.15^4)
See attached pic
=> <=
r=2.2
h=4.9
T= 37 Celsius
Ten= 65 Celsius
emissivity= 0.81
For the surface area I used:
A= 2 pie r^2 + 2 pie r h
I converted both r and h into meter
For the thermal radiation transfer I used the following equation
P= Stefan-boltzmann constant X emessivity X surface...
Question
Suppose that you release a small ball from rest at a depth of 0.610 m below the surface in a pool of water. If the density of the ball is 0.290 that of water and if the drag force on the ball from the water is negligible, how high above the water surface will the ball shoot as it...
I'm going to ask my professor about that problem. Thank you though. Could you have a look at the first problem in my first post ?
I'm pretty sure I need to find Rth using a test source but I can't seem to do it right. (A web form tells me my answer is wrong)
What I tried, I added a current...
Yes it turns out my answer is correct and that they forgot to ask for the answer in kilo ohm.
Can anyone tell me why the the Vth is equal to the v in the dependent source "3V"
A solution says i = \frac{5-3V}{2000} = \frac{5-3Vth}{2000}
Electric Circuit. Norton/Thevelin Equivalents
Unsolved Problem
I used a node voltage equation to try and get Vth and the I in the short-circuit to get the Rth but it didn't work.
Unsolved Problem
I used a node voltage equation to get Vth and I in the short-circuit. Got Rth and...