Science Infoblog » Year 11 Science Posts

Forces and acceleration (1)

john west — Thu, 06 Aug 2009 00:01:15 +0000

Top Gear and the Vampire, the ultimate acceleration on four wheels

…..and now the maths and science.

Vampire: technical information
estimated top speed; 370 mph
acceleration 0 to 272 mph in 6 seconds
engine; Rolls Royce Orpheus.
fuel economy: 7-10gallons per mile
Weight 2,200lbs(998Kg)
length 30 feet (9.14m)

Challenge: apply your science with some mathematics

Apply the science you have been studying to answer questions abouth the vanpire. Click on the comments button at the foot of this post and leave your answers.

The first 6 mostly correct answers will receive a mars bar (year 11 students or younger)

calculate the top speed in metres per second
calculate the acceleration in metres per second per second
The acceleration is produced by an unbalanced force. Calculate the thrust produced by the Rolls Royce Orpheus engine for this unbalanced force.
Why is the thrust produced by the engine actually much greater?

Motion and graphs, acids and bases, more from Shelley Dudley’s class

john west — Thu, 30 Jul 2009 08:44:24 +0000

Year 10 students studying NCEA level science this year have made a number of 5 minute tutorials that cover aspects of their course. Have a look at them. The first video deals with acids and bases.

The second video covers motion and distance time graphs. Do you find these tutorials useful. Why don’t you pick a topic with some friends and make your own video.

Virus replication and Mexican swine flu..H1N1 influenza A (flu) virus

john west — Tue, 26 May 2009 10:33:47 +0000

Mexican swine flu has a complex ancestry containing parts from two previous swine flu viruses and gene segments that originated in birds or humans. The strain of the virus derives its name from the proteins found on the surface of the envelope in this case haemagglutinin (H) and neuraminidase (N. These proteins determine the type of host cell the virus will latch on to.

For NCEA level 1 science you need to be familiar with the process of virus replication.

Bacterial Basics

john west — Sun, 24 May 2009 08:33:18 +0000

Check out the following:

Bacterial basics
How bacteria live: Extra cellular digestion
Watch a white blood cell chase a bacterium and absorb it…a horrible end
Bacteria dividing

NCEA Level 1 Geology: The Rock cycle and erosion and transport by glaciers

john west — Mon, 27 Apr 2009 10:07:24 +0000

Glaciers move slowly but relentlessly down valleys gouging out huge volumes of rock as they go. It takes about 400 years for snow collecting at the top of Fox glacier to reach the Fox river at the bottom.

As the glacier rips rocks away from the sides of the valley it can leave a polished surface with gouge marks. 400 years in this grinding machine can turn rocks into flour. Look at the colour of the water coming out the end of the glacier in the last video. Rocks carried by the glacier get dumped at the front and the sides when the ice melts.
Valleys formed by glacier erosion have a characteristic U shape.

NCEA Level 1 Geology: Te Henga….the last 20 million years

john west — Fri, 24 Apr 2009 00:01:01 +0000

Te Henga on Aucklands west coast is a neat spot. It’s peaceful present conceals a violent volcanic past stretching back more than 20 million years.

NCEA Level 1 Chemistry: Quiz, reactions of metals

john west — Mon, 06 Apr 2009 22:20:27 +0000

Test your knowledge about metal chemistry here.
reactions_of_metals

NCEA Level 1 Chemistry: The thermite reaction…for chemistry geeks!

john west — Mon, 06 Apr 2009 10:48:22 +0000

Metals combine with oxygen to form metal oxides. For example iron wool burning in oxygen produces iron oxide

The chemical equation.

Iron + Oxygen –> Iron oxide

Aluminium + Oxygen –> Aluminium oxide

Aluminium is reactive enough to chemically combine with oxygen atoms that are already attached to another metal atom.

Aluminium + Iron oxide –> Aluminium oxide + iron

This is known as a thermite reaction . A huge amount of heat is given out and the iron formed is molten. The reaction has been used by NZ rail to weld continuous sections of line together.

Year 11 Geology: plate tectonics, subduction zone North of NZ to Tonga

john west — Mon, 30 Mar 2009 08:55:59 +0000

North of New Zealand the Pacific tectonic plate is being subducted beneath the Australian plate. There is a lot of volcanic and earthquake activity along the collision zone.

Deep trenches form at the leading edges of subduction zones. If you watch as the pointer moves around the screen on the video and look at the elevaton numbers at the bottom ( they are negative so indicate the depth below sea level) the sea depth reaches 22,000 feet just east of tonga.

Tonga lies on a tiny microplate trapped as a rise between a spreading zone to the west and the subduction zone to the east. Recent volcanic activity appeared 10 kilometers from the southwest coast of Tongatapu, the main Tongan island. There are 36 other underwater volcanos in the vicinity.

NCEA Level 1 Chemistry: The reactivity series

john west — Mon, 30 Mar 2009 08:35:29 +0000

Some metals are clearly very reactive. Sodium and lithium react violently with water and calcium dissolves quickly.
Other metals dissolve in acids and the rate at which they dissolve tells you something about how reactive they are. If they give off lots of bubbles rapidly they are reactive. Aluminium is out of order because it has a protective layer of oxide. It appeqars to be unreactive and this fact often crops up in NCEA level 1 exams.
A list of metals from the most reactive to the least reactive is known as the reactivity series.