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  1. L

    Draw a ray diagram

    A converging lens has a focal length of 25cm. A 1.00cm tall object is placed 15.0cm in front of the lens. Find the image location and size, and describe it. Draw a ray diagram. Ok so I get 1/p + 1/q = 1/f rearranged for q=pf/p-f which equals -37.5, so the object is 37.5cm behind the lens. and...
  2. L

    Converging lens

    A converging lens has a focal length of 25cm. A 1.00cm tall object is placed 15.0cm in front of the lens. Find the image location and size, and describe it. Draw a ray diagram. Ok so I get 1/p + 1/q = 1/f rearranged for q=pf/p-f which equals -37.5, so the object is 37.5cm behind the...
  3. L

    How do you find the angle of polarization? What is the formula?

    ok the question reads exactly like this Find the angle of polarization and the corresponding angle of refraction for ethyl alcohol. That is all it says.
  4. L

    Fraction Of The Intensity Incident

    Just want to know if anyone has an idea if this is correct?
  5. L

    How do you find the angle of polarization? What is the formula?

    the angle of polarization of ethyl alcohol.
  6. L

    How do you find the angle of polarization? What is the formula?

    How do you find the angle of polarization? What is the formula? Its not in my physics book and I looked online and couldn't find it.
  7. L

    Fraction Of The Intensity Incident

    Two Polaroid filters are initially crossed. The analyzer is rotated through an angle of 55.0 degrees. Find the fraction of the intensity incident on the polarizer which passes the analyzer. I used I1=1/2 Io I2= I1cos I2= 1/2 Io cos^2(theta) = 1/2 Io cos227.5° = .393 Io Is...
  8. L

    Calculate power produced in each bulb

    Even though it says to ignore the series connection?
  9. L

    Calculate power produced in each bulb

    Not Wanting you to do it for me Actually I was reviewing for a test and working the odd problems. I was checking to see if I did them right. You guys always seem to assume the worst!!!!
  10. L

    Calculate power produced in each bulb

    Given two light bulbs with the following ratings: 75.0W 120VAC and 100W 120VAC. They are connected in series across a potential difference of 120. VAC. Assuming that the operating resistances of the bulbs are not affectd by the series connection, calculate (a) the power produced in each bulb...
  11. L

    Use galvanometer

    A galvanometer of 90 ohms internal resistance has a full-scale current of 350. microA. Describe how to use this meter to make : (a) a 150 V voltmeter, and (b) a 10.0A ammeter So (a) Resistors must be connected in series with the galvanometer, R=4.29 x 10^5 ohms. (b) A shunt resistor must...
  12. L

    Repulsive force

    Find the repulsive force on two protons in the nucleus of an atom assuming they are separated by the minimum distance of 1.00 x 10^-15m. So F=k lq(1)l^2/ r^2 =8.99 x 10^9 (1.602 x 10 ^-19)^2/(1.00 x 10^15m) =230.7N Is this correct?
  13. L

    Black body

    Ok that makes more sense!! And the problem reads just as I wrote it.
  14. L

    Temperature change boiling water

    Oops! so (.1450)(4.186)(5.2) +(.070)(.385)(5.2) +(m)(.44)(-74.8) which gives me 3.296384=32.912m which gives the mass to be .100kg this makes more sense thanks!!
  15. L

    Linear Expansion

    ok so .18=(215m)(12*10^-6)(T(f)-(-15)) and 69.767=T(f) +15 Finally T(f)=54.8 degrees C. Is this correct??
  16. L

    Temperature change boiling water

    Ok so I've got (.1450)(4.186)(5.2) +(.070)(.85)(5.2) +(m)(.44)(-74.8)Which gives me 8.8194=2.912m and m=.255kg So the iron cylinder is going to have more mass than the water and the calorimeter????
  17. L

    Calculate the ideal (Carnot) efficiency of a heat engine

    Or would you have to include the 1 in the efficiency equation again?
  18. L

    Linear Expansion

    Yes sorry I forgot the m. So are there two answers? And the bridge would have to move from 18cm to 215m for the second part that seems improbable.
  19. L

    Temperature change boiling water

    Ok so is that the right equation because it keeps giving me a negative
  20. L

    Melting ice

    So it would be m(333.7kJ/kg)+(.320kg)(4.186kJ/kg*K)(-68.0K)=.273kg of ice Is this correct?
  21. L

    Melting ice

    How much ice could be melted by 320. grams of water at 68.0 degrees C? Would I us mL + mcT=0 for the equation, and do the latent heat of ice for the first part and water for the second?
  22. L

    Black body

    How many times more energy is emitted from a black body at 550. degrees C than at a room temperature of 22.0 degrees C. So I know that a double in temperature increases energy by 2^4=16 so would I just do 25^4=390625 for this problem?
  23. L

    Linear Expansion

    A 215.m steel bridge has an expansion joint of 18.0cm at one end at -15.0 degrees C. At what temperature would the joint be closed? I would use the equation Change in L=L(alpha)T But would the L equal zero since the joint is closed?
  24. L

    Temperature change boiling water

    An iron cylinder is heated to 100.degrees C in boiling water ant then transferred to 145.0 grams of water in a 70.0 gram copper calorimeter at 20.0 degrees C. If the final temperature is 25.2 degrees C find the mass of iron used. Would I use mL(Boiling water)+mcT(water)+mcT(coper...
  25. L

    Change in Internal Energy

    Ok so what I've got is 3.35kcal=3350cal=3350cal*1J/.289cal=14022.604J Then U=14022.604J-90J=13092.604J and this is my change in internal energy. Is this correct
  26. L

    Calculate the ideal (Carnot) efficiency of a heat engine

    So for efficiency e =1-T(c)/T(h)=1-(298.18/788.15)=62.171% And for the heat rejected .62171=x/1.00*10^6=6.22*10^5 cal. Is this right
  27. L

    Calculate the ideal (Carnot) efficiency of a heat engine

    Calculate the ideal (Carnot) efficiency of a heat engine operating between 23.0 degrees and 515 degrees. How much heat would be rejected by the engine if 1.00 x 10^6 calories were taken from the high temperature resivoir. Would you just use e=1-(T(c)/T(H))? And for the second part i don't...
  28. L

    Change in Internal Energy

    I wasn't sure if Q=3.35Kcal. Does it equal only that? And I don't even know what the answer is supposed to be, its just usually all our problems are more difficult that i didn't know if there was something else to it.
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