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  1. C

    General algebra-

    Thanks slider :smile:
  2. C

    General algebra-

    Homework Statement Hi- this is actually part of my physics homework, but all I need help with deals strictly with algebra. This is my equation: (0.97)(1 + Beta gas (-Ti)) = (1 + Beta steel (-Ti)) Homework Equations The Attempt at a Solution How do I solve for Ti...
  3. C

    Ideal gas law-

    Thank you BF.
  4. C

    Ideal gas law-

    V = P/T m^3 or liters = Pa or (N/m^2) / (C) I'm still don't understand how it works out. Do you mean work it out with the n and R included?
  5. C

    Ideal gas law-

    Homework Statement A child holding a helium filled balloon @ sea level (T= 20 C) lets go of the string. The balloon rises freely several thousand meters, where T = 5 C and P = 0.70 atm. Find the percentage change in the balloon's volume. Homework Equations PV = nRT percentage...
  6. C

    Ideal Gas Law- finding gas density

    Thanks so much!!! I worked it out then referenced to the actual density of radon that I found online and it agrees :wink: Thanks again AM.
  7. C

    Ideal Gas Law- finding gas density

    Homework Statement What is the density of radon gas at 0 degrees C and 1 atmosphere? Homework Equations PV= nRT 0 C = 273 K density = mass/volume g/m^3 The Attempt at a Solution I want density = g/m^3 Below are the units of PV = nRT. I thought that breaking it down...
  8. C

    Simple Harmonic Motion- From Uniform Circular Motion

    Ok...I'll sit down with that thought. So, either one works right? They are the same thing??
  9. C

    Simple Harmonic Motion- From Uniform Circular Motion

    Ok- but in the book it gives: W = sq. root of (k/m) Instructor gives: W = 2pi x sq. root (k/m) Whats with the 2 pi?? Thanks-
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    Simple Harmonic Motion- From Uniform Circular Motion

    Homework Statement I don't have a homework question exactly, but I need help with an equation please. Angular frequency: W= 2 pi/T = 2(pi)(f) f= frequency And- W = square root of (k/m) k = spring constant m= mass So, wouldn't T = 2 pi / square root of (k/m) ?? My...
  11. C

    Angular velocity- pendulums and ideal springs

    Awesome- very helpful! Thanks so much.
  12. C

    Angular velocity- pendulums and ideal springs

    Why 10 degrees? I know all of this relates back to the angle that the path swings out somehow. Would it be the same if I did say, a 45 degree angle (easier to meausre) and then counted 45 cycles and divided by 45? What does the angle have to do with it??
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    Angular velocity- pendulums and ideal springs

    Homework Statement Suppose you were kidnapped and held prisoner by space invaders in a completely isolated room, with nothing but a watch and a pair of shoes (with shoelaces of known length). Explain how you might determine whether this room is on earth or on the moon. Homework Equations...
  14. C

    Simple Harmonic Motion and the Reference Circle

    Ok- I guess that makes sense. However, in other contexts I would probably still be confused with the cycles, revolutions, etc... I just can't wrap my head around it- silly I know :shy: I have some more problems to practice with. Thank you both, chrisk and LP- :smile:
  15. C

    Simple Harmonic Motion and the Reference Circle

    Ok one last question- how exactly do the units work themselves out? This is what I have: 1.89 x 10^5 rad = 2 pi rad/cycle To isolate cycle don't I have to multiply by 2 pi on each side? Even then I would be left with 1/cycle? You said to divide by 2 pi rad/ cycle, but then what's left...
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    Simple Harmonic Motion and the Reference Circle

    Ok, so when I plug numbers into W = 2pi (f) - or do it the way I stated in my previous post (same thing) I end up with this numerical value: 1.89 x 10^5 rad = 2 pi rad Is this correct? Can you please help me understand what this means? Do I need to divide through on the left by 2 pi? If...
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    Simple Harmonic Motion and the Reference Circle

    So, would it make 1 revolution (2 pi) in 2.5 seconds? I'm really confused I guess- what I just said doesn't make sense, becuase if it did, then the answer would just be 1, which didn't take the ang. frequency into account. What about this: W = 2 pi/T so 7.54 x 10^4 rad/sec (2.5 sec)...
  18. C

    Simple Harmonic Motion and the Reference Circle

    Homework Statement A loudspeaker diaphragm is producing a sound for 2.5 s by moving back and forth in simple harmonic motion. The angular frequency of the motion is 7.54 x 10^4 rad/s. How many times does the diaphragm move back and forth? Homework Equations angular freq. (W for...
  19. C

    Buoyancy of a raft

    Thank you so much for all of your help, LP :smile:
  20. C

    Buoyancy of a raft

    Ok :) Now another issue I am having. I took the force the raft can support, which is in newtons, as is the weight of the raft. So, how do I figure how many 60 kg persons this thing will hold? I thought it would be a simple conversion, but Im missing something somewhere. I did this: (1...
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    Buoyancy of a raft

    Alright- so, I found the bouyant force, and then the weight of the raft, so the rest of the weight can go to people. So, what does the whole, "and not get their feet wet" bit have to do with this? Does it just mean that if we go over our "account balance" that the raft will sink? So, the raft...
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    Buoyancy of a raft

    But I thought I just found the weight of the raft with the equations in my last reply... How do I find out the TOTAL weight I'm allowed??
  23. C

    Buoyancy of a raft

    I can't quite wrap my mind around what your saying. However, if it's of any help to get me started, I think I found the weight of water displaced by the raft. I used: m = roh x V then used W = mg. Is this correct?
  24. C

    Buoyancy of a raft

    Homework Statement A raft is made of 11 logs lashed together. They are 38.0 cm in diameter and 6.10 m long and has a density of 700 kg/m^3. How many 60 kg persons can the raft hold in freshwater while keeping everybody's feet dry? Homework Equations Volume immersed/Volume total =...
  25. C

    Bouyant force and apparent weight

    Ok- here's what I got, but Im not sure what this implies... mg + roh x V x g -mg = 0 mg cancels and I end up with roh x V x g = 0
  26. C

    Bouyant force and apparent weight

    Homework Statement This question is continued from a problem that I have already solved. This is what I know from the previous problem that will be helpful: r= 0.20 m roh of solid sphere= 850 kg/m^3 mass sphere= 3.94 x 10 ^-5 kg I also have 2 apparent weights that I solved for when...
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    Angle Ratios

    With everything I knew I was able to form two triangles and in each I knew two sides. A: 8.5 and 25 and hypotenuse unknown. B: 58.5 and 75 and hypotenuse unknown. Using the tangent inverse, I found theta for each.
  28. C

    Angle Ratios

    thank you! do these angles sound reasonable?
  29. C

    Angle Ratios

    Homework Statement Tree A is 10 m tall. Tree B is 60 m tall. You're standing on level ground at a position that is 25 m from tree A and 75 m from tree B. You're eye height is 1.5 m above the ground. Find the ratio of theta B/ theta A, of the angles (measured from the horizontal) at which you...
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