Recent Changes

Tuesday, March 20

  1. 12:47 pm

Thursday, March 1

  1. 6:28 pm

Tuesday, February 27

  1. page home edited ... {earthrise.jpg} Year 12 Science Welcome This site will be disappearing in July. I have mad…
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    {earthrise.jpg} Year 12 Science
    Welcome
    This site will be disappearing in July.
    I have made an HTML backup copy of it, but have no plans to replicate the site on a different platform at present, as I no longer teach this subject.
    If you wish to contact me about the site closure my email is pkeestra@sacredheart.school.nz

    My school is using a mix of ESS and other standards for a "12 Science" course. At the Auckland teachers meeting, I was asked to keep this website going so we could use it as a 'gathering place' for resources. I will also be writing 'textbook pages' for some of the new standards, as I did for the old course.
    The links for new pages are on the left and will turn blue when I have created the pages.
    (view changes)
    12:36 pm

Monday, October 17

  1. page Electricity edited ... {Static Electricity written questions 1.pdf} Two of the same charge i.e. positive and positi…
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    {Static Electricity written questions 1.pdf}
    Two of the same charge i.e. positive and positive or negative and negative, repel each other (exert a 'push' force). Once again, the size of the force is bigger for a bigger sized charge and at a closer distance.
    Either{water_bending.jpg}
    Either
    a positive
    ...
    force on ansome types of uncharged object e.g. a balloon that has been rubbed to charge ite.g.rubbed pen can make a streamattract bits of paper. It can also attract water bend towards it:
    {http://www.massacademysciences.org/sites/massacademysciences.org/files/bending%20water.jpg} Something
    as shown in the picture.
    Something
    that has
    Remember that electrons are negative.
    objects that have a surplus of electrons will be negatively charged
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    Magnetism and electromagnetism
    {http://www.parentinghealthybabies.com/wp-content/uploads/2015/06/Magnet-Paperclip.jpg}
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    termed ferromagnetic, andand are attracted
    Iron is the best known magnetic substance, but nickel, cobalt, various alloys and the oxide of iron known as ferrite or magnetite are all capable of being attracted to magnets or made into magnets.
    The attractive force produced by a magnet is due to a magnetic force field we will discuss in more detail later.
    ...
    {http://universitylabkit.com/uploads/3/6/1/1/3611687/3902825.jpg?500}
    (notes in preparation, use text in the interim)
    {right_hand_grip_rule.png}
    Electromagnetism
    A wire carrying an electric current has a magnetic field around it. The direction of the field is shown in the picture: The field lines are circles that run anticlockwise if the current is coming towards you. The other way to think of it is that the field lines go in the direction that your fingers curl if you hold the wire with your right hand and your thumb pointing in the direction of the current. This is called the "right hand grip rule".
    {wire_compasses.png}
    A compass placed on the piece of paper illustrated would have its needle pointing in the directions of the field lines at that point.
    The magnetic field is strongest close to the wire and reduces in direct proportion to the linear distance.
    Magnetic field strength is given in units called tesla. The symbol for tesla is T. A field of one tesla is extremely strong; even a rare earth magnet has a field of only a few millitesla at the strongest.
    The magnetic field strength is calculated using the formula
    {tesla_formula.png}
    In this formula, B is the magnetic field strength in tesla; I is the current in amps and d is the perpendicular distance from the wire in metres.
    The "k" in this formula is a constant Constants are things that are needed in formulas to make the answer come out in the right size and units for a particular situation. For example,. you have used the formula F = mg to calculate the force on an an object of mass m due to gravity. The value of g we use is 9.8 N kg-1. This value is approximate and is only true for Earth; it would be different on Mars. The units for g (of ) are needed to make the answer come out in newtons.
    In the magnetic field formula the constant k stands for a constant that only applies in air or a vacuum; it would have a different value in different situations. The value of the constant is k = 2 x 10-7 T m A-1. The units of this are the units needed to make the answer come out in tesla if you use current in amps and distance in metres. Note that an alternative way of writing this is k -2 x 10-7 T N A-2.; this would give you an answer in N A-1 m-1 (which is actually another way of writing tesla). This is similar to the way that the constant "g" can be written as g = 9.8 N kg-1 or g = 9.8 m s-2 , They are mathematically equivalent but written in different ways.

    Review of this unit
    Electricity workbook: note you must be logged into your SHC Google account for this link to work. Can I suggest you download the PDF and load it up either into your own Google Drive folder or into an external application you can use to write on it e.g. Notability (Apple)
    (view changes)
    3:58 pm
  2. 3:45 pm
  3. 3:38 pm
  4. 3:27 pm

Thursday, September 15

  1. page earth physics edited ... {Earth's heat sources 2012.ppt} {light scattering 2012.ppt} ... students only Answers (…
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    {Earth's heat sources 2012.ppt}
    {light scattering 2012.ppt}
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    students only Answers (note - 6 Mb file on Google Drive, private to SHC)
    I am moving in some material from the old L3 Science/Physics standard; some links have been lost. I will rebuild this as I have time.
    To get the full material go to:
    (view changes)
    3:06 pm

Monday, September 12

  1. page extremophiles edited ... Google Doc logbook: accessible to SHC students PDF logbook {logbook.pdf} {extreme environ…
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    Google Doc logbook: accessible to SHC students
    PDF logbook {logbook.pdf}
    {extreme environment student booklet 2016.pdf}
    (view changes)
    5:49 pm

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