Digestive System Powerpoint
This is the link to the document:
https://docs.google.com/present/edit?id=0AViV8cbBcGW9ZGZ0d3R3andfMmZ3bnI1N2h0&hl=en_US
Australian Special Mammals Powerpoint
This is the link to the document:
https://docs.google.com/leaf?id=0B1iV8cbBcGW9OWRmM2RjNDgtOTA4Mi00ODAxLWJlM2EtZTlmYjYwYmUwMjg1&hl=en_US
Rouge Waves Powerpoint
This is the link to the document:
https://docs.google.com/leaf?id=0B8OBAIfhCiCeNDYxNGZmMWItMGI5MC00ZDZhLTk1NmEtZjRiY2VkNWQ2YzJi&hl=en_US
Gimli Glider Incident
Gimli Glider is a nickname of the Air Canada aircraft that was involved in a notable aviation incident. On 23 July 1983, Air Canada Flight 143 ran out of fuel at 7920m altitude, halfway through its flight from Montreal to Edmonton via Ottawa. Fortunately, the crew managed to steer the aircraft to safety by lauching an emergency landing at Glimli Industrial Park Airport.
Subsequent investigations showed that a series of human errors resulted in this incident. They had incorrectly calculated the amount of fuel needed to fill the fuel tank. In addition, fuel loading was miscalculated through misunderstanding of the recently adopted Metric System, which replaced the imperial system.
At 7900 m over Red Lake, Ontario, a warning which indicated a fuel pressure problem on the engine’s left side sounded. It was only after the second fuel pressure alarm that the crew realised that the calculation of the fuel was based on incorrect settings, which meant they had not enough fuel to complete the entire journey of the flight. After much communication with the crew, they made a crucial decision – to land at Glimli Industrial Park Airport.
Although the decision was made, there were many difficulties faced by the pilot and its crew to land safely. The pilots tried lowering the aircraft main landing gear via a gravity drop, but, due to the airflow, the nose wheel failed to lock into position. As the runway drew closer, the aircraft was too high and fast, raising the danger of running off the runway before the aircraft stopped. The pilot also attempted to reducing the speed of the aircraft for a safe landing by utilising a flap extension, but to no avail. As soon as the wheels touched the runway, the pilot stood on the brakes. Fortunately, they were able to slow the aircraft down and they had miraculously survived the ordeal with none of the passengers hurt.
What happened?
At the time of the incident, Canada was converting to the metric system. For the trip to Edmonton, the pilot calculated a fuel requirement of 22,300 kilograms. A dripstick check indicated the there were 7682 litres already in the tank. They thus had to find out had much fuel needed to be added.
A litre of jet fuel weighs 0.803kg, so the correct calculation was:
7682 litres × 0.803 = 6169 kg
22300 kg − 6169 kg = 16131 kg
16131 kg ÷ 0.803 = 20088 litres of fuel to be transferred
However, they arrived at an incorrect conversion factor of 1.77, the weight of alitre of fuel in pounds. Hence, they produced an incorrect calculation:
7682 litres × 1.77 = 13597 kg
22300 kg − 13597 kg = 8703 kg
8703 kg ÷ 1.77 = 4916 litres of fuel to be transferred
Instead of 22,300 kg of fuel, they had a mere 22,300 pounds on board — only a little over 10,000 kg, or less than half the amount required to reach their destination. This thus led to the aircraft having not enough fuel to complete their journey and hence resulted in a minor incident.
Through these minor incidents, we can understand that minor mistakes in our everyday lives can resulted in a major catastrophe. Hence, we have to be extremely careful in doing our work, so as to prevent such incidents from repeating itself.
Try to explain why your egg sunk in tap water but floated in tap water
In order for something to float, the buoyant force has to be greater than or equal to the weight of the object. The buoyant force is equal to the weight of the liquid that is displaced by the object. To figure out the weight of the water displaced you multiply the density of the water by the volume and then multiply that by gravity. The density of the fresh water is less than the density of the salt water, therefore the weight of the water displaced will be greater in the case of the salt water, resulting in a greater buoyant force.
The more salt in water the more bouyant an object becomes. The salt makes the water more denser. The density of the salt water is greater than the density of the egg. Items sink if their own density is greater than the density of whatever they are trying to float in. Items float to the top if their density is less than the density of what they are floating in, and items hang in the middle if the densities are the same. Adding in the salt gives the water a greater density than the water did had before (I have explained in my previous post), so the egg doesn't float in freshwater.
Why and how did the density of water change when salt was added to it?
Salt is a form of matter and has mass. Hence, when salt was added to freshwater, the mass of the saltwater would definitely be more. And since the volume of the water does not change, the density of the saltwater will increase. (Take for example the mass of the water is 200g, the mass of the salt is 100g and the volume of water is 100cm3. Hence, if you take 200 divided by 100, the density of the water is 2g/cm3. However, when salt is added, the mass of the saltwater is 200+100=300g. And if you take 300g divided by 100, the density of the saltwater thus increases to 3g/cm3)
Science Lab Safety Poster
This is the link to my science lab safety poster:
https://docs.google.com/document/d/1E8JXy5dwCwo48iZtG2MupobognjdQ0g9kNwVBcqJdZg/edit?hl=en&pli=1
