Search results

  1. B

    Young's Modulus Question

    1. Homework Statement A nano-tube having cross sectional area A and length L extends ΔL when a force F is applied normally to one of the cross-sectional surfaces. Show that if N tubes are connected end-to-end the then Young's modulus of the fibre does not change. 2. Homework Equations 3...
  2. B

    GPS Altitude

    Thanks for such an informative post! Pressure sensors do seem ideal for aviation rather than gps.
  3. B

    GPS Altitude

    Yes I guess when it comes to my self guided quad-copter i'm going to have to set the initial altitude to the reference or maybe use an external altitude sensor.
  4. B

    GPS Altitude

    russ_watters, that link you just sent me explains a lot. Hence the readings I obtained. Thank you for your help! And sorry about that daven my bad!
  5. B

    GPS Altitude

    I'm a programmer/electronics student and I recently bought a GPS which I hooked up serially with my laptop. I didn't get into much detail of encoding the string which is output from the TX/RX pins of the GPS so I downloaded, a ready made program called "ublox 6". Longitude and latitude are...
  6. B

    Thermodynamics First Law Question

    Thank you so much! That helps a lot. :)
  7. B

    Thermodynamics First Law Question

    Thanks for your reply! Alright I see what you mean. Second attempt: Number of moles in gas using ideal gas equation: R= 8.314 4621 J mol-1 K-1 (Given in exam paper booklet): n=(PV/RT) n=(1.5x105Pa*1.25x10-3m3)/(8.314*300K) n=0.075 Change in temperature using Charles law would be: 372K...
  8. B

    Thermodynamics First Law Question

    1. Homework Statement Can someone help me confirm if I answered correctly please? a) A sample of gas is enclosed in a cylinder by a piston. The cylinder is given 225J of energy which expands and pushes the piston 16cm outwards against an atmospheric pressure of 1.01x105Pa. i) give the...
  9. B

    Heat Transfer and capacity

    Sorry lagg. Ignore this post.
  10. B

    Heat Transfer and capacity

    (Heat lost changing state + Heat lost due to change in temperature) = Heat Gained When changing water to steam it would be heat required. But when steam is changed back to water, is it heat energy gained or lost?
  11. B

    Heat Transfer and capacity

    Oh alright this makes more sense now. So the mass is:8.6x10-3kg
  12. B

    Heat Transfer and capacity

    I'm confused, now I get the idea that its written like this? (ml+cΔT)=mc∆θ
  13. B

    Heat Transfer and capacity

    Oh right. mc∆θ=mc∆θ m*4200*2.26x106Jkg-1*(100-80)=0.08*4200*(60) m=1.06x10-7kg Q=ml is the energy used to convert the water into steam and vice versa without a change in temperature, and the specific heat capacity * change in temperature indicates the heat lost?
  14. B

    Heat Transfer and capacity

    Like this? Sorry if I might be frustrating you, I don't blame you. Left side is the water added to the cup, assuming the water is at 100C. mc∆θ=mc∆θ m*4200(100-80)=0.08*4200*(60) m=0.24kg
  15. B

    Heat Transfer and capacity

    Oh right so I should just re-write it like this? m*lf=mc∆θ lf being the latent heat of fusion.
  16. B

    Heat Transfer and capacity

    Sorry I arranged the units. Heat Lost = Heat Gained mc∆θ=mc∆θ m*2.26x106Jkg-1*20C=0.08kg*4200*60C m=4.46x10-4kg 20 and 60 are the change in temperature. Is this correct?
  17. B

    Heat Transfer and capacity

    Heat Lost = Heat Gained mc∆θ=mc∆θ m*2.26x106Jkg-1*20=0.08*4200*60 m=4.46x10-4kg Is this correct?
  18. B

    Heat Transfer and capacity

    Oh ok, that's a better understanding of the question c. Are the calculations correct?
  19. B

    Heat Transfer and capacity

    1. Homework Statement Is my approach correct? Thanks all :) a)The specific heat capacity of water is 4200Jkg-1K-1 while the specific latent heat of steam is 2.26x106Jkg-1. Explain what is meant by the statement in italics. b) Explain, in terms of molecular motion, the large difference between...
  20. B

    Gas Law Problem

    Sorry for late response, but since you pointed out where I had to improve, I manged to get this question right :)
  21. B

    Gas Law Problem

    1. Homework Statement Can someone confirm if I answered correctly? Thanks for support and help! a) In the Brownian motion experiment, small particles of matter are seen moving randomly. Give an explanation for this motion. b) Boyle's Law is fundamental when discussing the gas laws. i) State...
  22. B

    Gravitational fields

    Thank you sir for pointing that out, I'm assuming rest is correct then.
  23. B

    Gravitational fields

    1. Homework Statement Need someone to confirm if I answered correctly. Thanks for your support :) A) Draw the pattern of the gravitational flux passing through a horizontal surface A, of area 1m² close to the Earth's surface. B) What is meant by the phrase "Gravitational potential at a point...
  24. B

    Electrostatic field

    1. Homework Statement Can someone confirm if I answered correctly? Question: Two small identical spheres each carrying a charge, +q C, are placed on the line LM as shown in the diagram: Describe how the intensity and direction of the electric field produced by the two charges varies: i)...
  25. B

    Drift Velocity & Current

    Sorry Bi) Area: m2 Current: A Drift velocity: m/s Electronic Charge: C As for Ai) Since the electrons move in a zig zag fashion they will have change in directions & velocity. The drift velocity would be the resultant of these motions. I hope I have a good understanding of drift velocity, I'm...
  26. B

    Drift Velocity & Current

    1. Homework Statement Can someone confirm if I answered correctly? Thanks Ai) Define the term drift velocity with reference to a current in a circuit. ii) Derive an expression to describe the current passing through a metallic conductor of cross-sectional area A having n charge carriers per...
  27. B

    Charge, Current & Power

    Oh my bad, yes you are right. Holes travel the opposite direction from a higher potential to a lower potential. They too help with conductivity. Delta thank you for correcting my mistakes this helps me a lot. :)
  28. B

    Charge, Current & Power

    1. Homework Statement Can someone please confirm if I answered correctly? Question: According to rumours the next generation smart phone will be powered by a 3.82V battery that can deliver 1.81A of current for one hour. The phone automatically turns off when the battery has less than 2% of...
  29. B

    Hello World!

    Pretty high salary
Top