talked about shortcuts for differentiation today
if f(x) = x^n then f`(x) = nx^(n-1)
chyeah boi.
its all written down in the booklet thingy
usually what we do is when we're asked to differentiate
we write it like this.. say the question was
differentiate x^2
we would write
d/dx (x^2) = 2x^(1)
=2
right?
the x on the d/dx means thats what we're doing it in relation to, if there was a t in the question isntead, the bottom would say t. the top, represents the other thing.. if the question was
y = 5x^4 - 3x
then we would put dy/dx in instead. catch it?
also, any number without the number we're focusing on (next to the d at the bottom) just turns into a 0 when working it out
Tuesday, November 3, 2009
phys (1102) - Space: pendulum period formula
before we got stuck into more formula stuff, we first did a few HSC 2008 questions, which i did correct.
we talked about energy conversion in a rocket taking off.
chemical energy decreases, coz it is burnt up and converted to kinetic energy (which increases) and gravitational potential energy (which also increases)
even though its a negative value, it increases coz it gets closer to 0
as for kinetic energy, the movement of the rocket is because a net force acts on it, caused by the thrust of the engine.
if the rocket kept the same thrust, the rocket would keep accelerating, coz mass decreases, so for force to stay the same, acceleration increases (F = ma) full metal alchemist broz
so to slow down the rocket, the thrust is reduced (its important to keep an eye on acceleration coz some rocket equipment can die to pressure, so can people)
then we talekd about pendulums, the formula for period iiiiiisss..
T = 2(pi) root:(l/g)
yes thats crappy -.- but i have no symbols here haha.
and the gravitational force between any two masses isss..
F = G(m1m2)/r^2
yeah..
then we talked about weighto n other planets, which we did not finish this lesson
we talked about energy conversion in a rocket taking off.
chemical energy decreases, coz it is burnt up and converted to kinetic energy (which increases) and gravitational potential energy (which also increases)
even though its a negative value, it increases coz it gets closer to 0
as for kinetic energy, the movement of the rocket is because a net force acts on it, caused by the thrust of the engine.
if the rocket kept the same thrust, the rocket would keep accelerating, coz mass decreases, so for force to stay the same, acceleration increases (F = ma) full metal alchemist broz
so to slow down the rocket, the thrust is reduced (its important to keep an eye on acceleration coz some rocket equipment can die to pressure, so can people)
then we talekd about pendulums, the formula for period iiiiiisss..
T = 2(pi) root:(l/g)
yes thats crappy -.- but i have no symbols here haha.
and the gravitational force between any two masses isss..
F = G(m1m2)/r^2
yeah..
then we talked about weighto n other planets, which we did not finish this lesson
bio (1102) - MaB: [c] feedback mechanisms
today we sort of compared a simple feedback mechanism to other things.. like temperature regulation in computers and people.
two sites that i found most handy today though were:
http://www.bio.miami.edu/~cmallery/150/physiol/sf38x17.jpg
http://www.bio.miami.edu/~cmallery/150/physiol/c44x10thermo-reg.jpg
two sites that i found most handy today though were:
http://www.bio.miami.edu/~cmallery/150/physiol/sf38x17.jpg
http://www.bio.miami.edu/~cmallery/150/physiol/c44x10thermo-reg.jpg
ag (1102) - Lettuce: healthy plants
talked about a few things today
first we talked about what research does in terms of impacting plant production.
research its used to find new plant varieties (eg downy mildew resistant lettuce), machines (eg olive harvester), insecticides (eg fungal sprays), management tactics (like IPM) and planting densities and fertilizer rates.
we talked about qualitative and quantitative measurements for plants
a few qualitative factors for lettuce:
FREE OF INSECT PESTS, SNAILS AND SLUGS
- this can be achieved using pellets and insecticides
- one can clear typical hiding places of snailes etc, or use IPM which could include predatory insects such as wasps
- companion crops / aphid repellants such as parsley can be planted to keep aphids away (they dont like the smell)
UNIFORM SIZE AND HEALTHY APPEARANCE (COLOUR)
this can only be done with adequate nutrients (biggest determiner of healthy colour) and lots of water.
the last thing we did was look at pesticide labels, they all basicaly say the same thing in terms of safety. use only as directed, keep out of reach of children, call poisons info centre if you ingest it, if possible try force vomitting.
first we talked about what research does in terms of impacting plant production.
research its used to find new plant varieties (eg downy mildew resistant lettuce), machines (eg olive harvester), insecticides (eg fungal sprays), management tactics (like IPM) and planting densities and fertilizer rates.
we talked about qualitative and quantitative measurements for plants
a few qualitative factors for lettuce:
FREE OF INSECT PESTS, SNAILS AND SLUGS
- this can be achieved using pellets and insecticides
- one can clear typical hiding places of snailes etc, or use IPM which could include predatory insects such as wasps
- companion crops / aphid repellants such as parsley can be planted to keep aphids away (they dont like the smell)
UNIFORM SIZE AND HEALTHY APPEARANCE (COLOUR)
this can only be done with adequate nutrients (biggest determiner of healthy colour) and lots of water.
the last thing we did was look at pesticide labels, they all basicaly say the same thing in terms of safety. use only as directed, keep out of reach of children, call poisons info centre if you ingest it, if possible try force vomitting.
Sunday, November 1, 2009
phys (1030) - Space: [p] pendulum length
the class split into groups to do one length of string for the pendulum each.
our group did 0.8m.
each group measured the period for 4 trials then took an average.
all groups used the same mass ball on the end of the string to not rig up the results.
the experiment was to test whether length had an effect on the period of a pendulum swinging.
my prediction was longer ones would take longer, and thats what the class' results show.
our group did 0.8m.
each group measured the period for 4 trials then took an average.
all groups used the same mass ball on the end of the string to not rig up the results.
the experiment was to test whether length had an effect on the period of a pendulum swinging.
my prediction was longer ones would take longer, and thats what the class' results show.
bio (1030) - MaB: response pathways
not much talk during this lesson coz we were talking about assessments etc for a lot of it.
we just touched on response pathways, which we've been basically tlaking about so far anyway.
the receptors send pulse signals through nerves and up the spinal cord and to the brain. the brain returns a signal to the corresponding muscles to do an action (eg secrete sweat if its too hot)
also, i asked a rnadom question of interest.. coz our body temp likes being 37, but on a day of 37deg, we find it too hot already.
apparently theres no optimum temperature for the outside of our bodies, but it still likes to regulate temperature.. to adapt.
and the reason why its our arms and legs and face that goes red when it gets hot.. its because blodo vessels are close to the outside in these locations, tahts why they thicken when its hot.. its easiest for the heat to get out through here
we just touched on response pathways, which we've been basically tlaking about so far anyway.
the receptors send pulse signals through nerves and up the spinal cord and to the brain. the brain returns a signal to the corresponding muscles to do an action (eg secrete sweat if its too hot)
also, i asked a rnadom question of interest.. coz our body temp likes being 37, but on a day of 37deg, we find it too hot already.
apparently theres no optimum temperature for the outside of our bodies, but it still likes to regulate temperature.. to adapt.
and the reason why its our arms and legs and face that goes red when it gets hot.. its because blodo vessels are close to the outside in these locations, tahts why they thicken when its hot.. its easiest for the heat to get out through here
ag (1030) - Lettuce: randomization & standardization
today was discussion of the frequency distribution curve, as well as randomization and standardization.
we discussed that our frequency distribution curves kept the basic normal shape, coz they were tallest in the middle, and results were fewer on either end.
apparently randomization and standardization can alwayus be improved, thus we can always mention it when a question asks how we could improve an experiment
randomization colld have been improved by increasing the number of beds for each density we had. (eg 6 or 10 instead of 3)
standardization could have been improved if we measures precisely the amount of water/fertilizer/snail pellets we used.. since it was all estimated.
the rest of the lesson was spent killing our beds, that included our prized cabbage.
we discussed that our frequency distribution curves kept the basic normal shape, coz they were tallest in the middle, and results were fewer on either end.
apparently randomization and standardization can alwayus be improved, thus we can always mention it when a question asks how we could improve an experiment
randomization colld have been improved by increasing the number of beds for each density we had. (eg 6 or 10 instead of 3)
standardization could have been improved if we measures precisely the amount of water/fertilizer/snail pellets we used.. since it was all estimated.
the rest of the lesson was spent killing our beds, that included our prized cabbage.
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