SC Science 2011 MARATHON (1 Viewer)

[zombies]

ahahahahahahhaah oh gosh i think i'm gonna be so screwed for SC science

 

[bleakarcher]

Explain why power companies bother increasing the voltage of power lines if it is only going to be reduced again before reaching homes. (from a year 10 textbook)

y is this?

 

[twinklegal19]

I doubt that's part of the syllabus (since that's all BOS is going to test us anyway).
Anyway, it's because high voltage transmission is much more effective and efficient. Plus they can use transformers on the way.

Next question: Distinguish between absorption, reflection and refraction of light and identify everyday situations where each occurs.

Just curious, does everyone use Science Focus 4?

 

[dionb2014]

What are the most reactive and least reactive elements on the periodic table?
Natural selection also referred to as evolution, is the process by which only the strongest or most well adapted specimen will survive in the particular environment. As a result only the optimum genetics for this species will continue on allowing the species to improve over generations and generations.

 

[taylorswiftlove]

^u dont like biology, what about physics/chemistry?

I actually don't mind biology, it's chemistry that shits me. Knew absolutely nothing about chemical/compounds in year 10 and still don't!
haha I praise everyone that does chemistry, I would fail so badly

 

[Fizzy_Cyst]

Explain why power companies bother increasing the voltage of power lines if it is only going to be reduced again before reaching homes. (from a year 10 textbook)

Power loss is proportional to current squared. By using a transformer to step up the voltage, according to the Power equation (P=IV) and consevration of energy, if voltage is increased, current is decreased. Hence, by increasing the voltage, they are decreasing the current and thereby decreasing the amount of energy lost as heat through the power lines.

Question:
Define transitional fossil and give an example of one

 

[lath]

I doubt that's part of the syllabus (since that's all BOS is going to test us anyway).
Anyway, it's because high voltage transmission is much more effective and efficient. Plus they can use transformers on the way.

Next question: Distinguish between absorption, reflection and refraction of light and identify everyday situations where each occurs.

Just curious, does everyone use Science Focus 4?

I use SF4...absorption is when light is trapped in a substance e.g. opaque substances such as wood absorb light. reflection is when light bounces off a surface because it strikes at an angle greater than the critical angle e.g. red bike reflectors reflect incoming light from cars. refraction is the bending of light as it passes through different substances e.g. a ruler appears bent when immersed in water (apparent depth).

 

[dionb2014]

I doubt that's part of the syllabus (since that's all BOS is going to test us anyway).
Anyway, it's because high voltage transmission is much more effective and efficient. Plus they can use transformers on the way.

Next question: Distinguish between absorption, reflection and refraction of light and identify everyday situations where each occurs.

Just curious, does everyone use Science Focus 4?

Reflection is when the light waves bounce off another object, an example would be in a mirror. Refraction is when light bends as it changes speed like going through water, this is why an object at the bottom of a pool may not be true to life. Absorption is when light waves are taken in by a particular object and not reflected and does not exit out the other side but is "absorbed by it".

 

[lath]

What are the most reactive and least reactive elements on the periodic table?
Natural selection also referred to as evolution, is the process by which only the strongest or most well adapted specimen will survive in the particular environment. As a result only the optimum genetics for this species will continue on allowing the species to improve over generations and generations.

Bottom left and top right are most reactive (Fluorine and Francium)...least reactive is probz the noble gasses.

 

[bleakarcher]

Reflection is the re-direction of a ray of light off a smooth surface in the same angle at which it struck the surface ie the angle of incidence is equal to the angle of reflection in the case of reflection. Refraction involves the re-direction of a ray of light as it passes through a translucent/transparent object, exiting in a direction parallel to the direction at which the light entered.

I'm not really sure about absorption

 

[bleakarcher]

What are the most reactive and least reactive elements on the periodic table?
Natural selection also referred to as evolution, is the process by which only the strongest or most well adapted specimen will survive in the particular environment. As a result only the optimum genetics for this species will continue on allowing the species to improve over generations and generations.

natural selection is not referred to as evolution btw it is simply a form throughout which evolution can occur, just a heads up

 

[lath]

Power loss is proportional to current squared. By using a transformer to step up the voltage, according to the Power equation (P=IV) and consevration of energy, if voltage is increased, current is decreased. Hence, by increasing the voltage, they are decreasing the current and thereby decreasing the amount of energy lost as heat through the power lines.

Question:
Define transitional fossil and give an example of one

Is a transitional fossil preserved evidence of past life that suggests the evolution of an organism. not sure about examples.

Q) Is mitosis a form of asexual or sexual reproduction?

 

[dionb2014]

natural selection is not referred to as evolution btw it is simply a form throughout which evolution can occur, just a heads up

Oh thanks. I must have misinterpreted it, I won't get that wrong now so contributing was worthwhile haha.

 

[bleakarcher]

mitosis is a form of reproduction? lol

 

[LoveHateSchool]

Asexual for growth/repair

Honestly SC kiddies, watch some Big Bang Theory and have fun this weekend!

Give me a use for visble light and a use for ultraviolet light.

 

[dionb2014]

Is a transitional fossil preserved evidence of past life that suggests the evolution of an organism. not sure about examples.

Q) Is mitosis a form of asexual or sexual reproduction?

Mitosis is a form of asexual reproduction where a parent cell spits into two identical daughter cells.

 

[bleakarcher]

Asexual for growth/repair

Honestly SC kiddies, watch some Big Bang Theory and have fun this weekend!

Give me a use for visble light and a use for ultraviolet light.

lol, I'm going to start this week. I will do some for science and that will probably be it

 

[lath]

Asexual for growth/repair

Honestly SC kiddies, watch some Big Bang Theory and have fun this weekend!

Give me a use for visble light and a use for ultraviolet light.

Visible light - human sight and photosynthesis
UV light - air conditioning, vitamin D and killing bacteria.

lol ive already seen all episodes

 

[Fizzy_Cyst]

mitosis is a form of reproduction? lol

Yes?

It's how unicellular organisms replicate! so, asexual

Question:
What are the products formed when magnesium is dissolved in Hydrochloric acid

 

[bleakarcher]

magnesium chloride and hydrogen gas