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lilg132Best ResponseYou've already chosen the best response.0
\[v = {g \over k} (1  e ^{kt})\] v = velocity g = gravitational constant which is \[9.8 ms ^{2}\] k = (measured in \[s^{1}\] t = seconds what is e? in the equation
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
lanaaa to the rescue :p
 one year ago

lalalyBest ResponseYou've already chosen the best response.0
which course are u taking lilg/?
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
you know already ee can you help me?
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
i think it involves differentiation
 one year ago

lalalyBest ResponseYou've already chosen the best response.0
this is a differential equation and e^kt is the homogeneous solution
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
the value for k (s^1) is 0.15 the value of t you can say is 1 second
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
what would it be kte^kt?
 one year ago

lalalyBest ResponseYou've already chosen the best response.0
I still dont get what ur question is, why did u differentiate that? write down the full question lilg
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
its really long one minute
 one year ago

lalalyBest ResponseYou've already chosen the best response.0
Take ur time im not leavin:)
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
It is already known that objects falling under the influence of gravity obey the equations of constant acceleration, with a gravitational constant g (usually taken to be 9.8 ms ^2) that applies to all objects independent of their size or mass Under more realistic conditions, objects falling through air will quickly reach a state of constant velocity, this velocity, which depends on the size, shape, and mass of the falling object, is called terminal velocity. you are on a team developing parachutes for skydivers the velocity v (in ms^1) of a typical skydiver after t seconds is modelled by your team using the equation \[v = {g \over k} (1  e ^{kt})\] the value of k (measured in s^1) is used to model the different stages of the skydivers decent. The table shows some values found through the experimentation: TYPE OF MOTION k(s^1) Human in free fall 0.15 Parachute deployed 2.00 1) use a spreadsheet to plot the changing velocity over the 0 to 3 seconds for a parachutist 2) what is the terminal velocity for the skydiver? theres more questions but yes im stuck on 1 :p
 one year ago

JopHPBest ResponseYou've already chosen the best response.0
do u k anything abt Euler's formula ?
 one year ago

JopHPBest ResponseYou've already chosen the best response.0
e^x=e^z(cosy + i siny) this is the formula
 one year ago

lalalyBest ResponseYou've already chosen the best response.0
Jop euler cant be used here:S
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
http://en.wikipedia.org/wiki/Euler%27s_formula
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
e^2.00(1 second) = cos(1) + 2sin(1)
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
that would give me 1.223244275 (btw i made a mistake it should 2sin(1))
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
so \[{9.8 \over 2.00} (1.223244275)\]
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
but shoudn't it be \[{9.8^{2} \over 2.00^{1}}(1.223244275)\]
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
which gives you 0.02547364171
 one year ago

JopHPBest ResponseYou've already chosen the best response.0
i think it makes sense But i'm nt sure
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
but i also forgot to take in account that 2.00 should 2.00^s1 :S that confuses me the most
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
Is your question really just what e is?
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
thats one of my questions but i can see gets taken out using the eulers formula, if thats what im supposed to use in this. but i need help working out question 1 really
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
if someone can show me how they would write the equation out with the values that would help me understand alot better
 one year ago

experimentXBest ResponseYou've already chosen the best response.0
http://www.wolframalpha.com/input/?i=y+%3D+10%281++e^%282t%29%29+from+t%3D0+to+5
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
where did you get 10 from? and what about when it says k is measured in s^1?
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
Okay okay. Well, the question of what e is is not too hard. e is a mathematical constant. Its value is approximately 2.71828
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
ok thanks for that smoothmath
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
Yup. If you want to read more about it or understand why it's important, wikipedia is a good source, as always. http://en.wikipedia.org/wiki/E_(mathematical_constant)
 one year ago

experimentXBest ResponseYou've already chosen the best response.0
just putting arbitrary values ... e is Euler's constant ... your velocity should be increasing with constant acceleration ... but since air resistance is directly proportional to velocity .... after certain velocity .. your velocity remains constant ... just another decay equation!!
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
{lilg scratches his head}
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
1) use a spreadsheet to plot the changing velocity over the 0 to 3 seconds for a parachutist
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
I mean... I'm not fantastic at spreadsheets, but this is a simple problem as long as you are inputting the equation correctly.
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
what im mainly confused about is when i use these values in the equation FOR EXAMPLE g = 9.8 ms^2 to put it in the equation as 9.8^2 or just 9.8
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
and the same for k when it says it is measured in s^1 so i should just leave it as 0.15 or 2.00 instead of 0.15^1
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
When they say "ms^2" that's the unit only. \[ms^{2} = \frac{m}{s^2}\] Which is the saem as "meters per second squared."
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
also the end result v is in ms^1 so the end answer e.g. is 20 would i write it as 20^1 or just 20
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
Yup. Don't worry too much about the units here =)
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
soooo if you can just check one answer for me if its correct im going to use k = 0.15 and t = 1 second so i would get \[v = {9.8 \over 0.15}(1 + \cos(1)  0.15\sin(1))\] or is it  cos(1)
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
Those are units of measurement. If I ask you how much something costs, and you answer "20," I will get angry and ask you "20 WHAT?" Same thing here. Velocity is measured in meters per second, which can be written as \[\frac{m}{s}\]
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
Oh my god no no no. Ignore that fancy pants crap those other people were giving you. That's just making the problem complicated. Just plug in the right values to the original equation and solve.
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
can you show me how you would plus in the values in the equation please it will help me understand much better
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
use the value of k = 0.15 and t = 1 second
 one year ago

rs32623Best ResponseYou've already chosen the best response.0
are u asking the value of e? it is approximately equal to 2.71..
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
Sure. k = .15 t=1 \[\frac{g}{k}(1e^{kt}) = \frac{9.8}{0.15}(1e^{0.15*1})\]
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
Easy peasy. Plug in and solve. Make sure to use the correct order of operations and keep track of signs =)
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
do i not use eulers formula then?
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
when i have e^0.15*1 what do i do with that?
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
You don't need to, so I don't see why you should.
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
\[a^{x} = (\frac{1}{a})^x\]
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
so would it be \[({1 \over e})^{0.15}\]
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
That's the rule for negative exponents. Take the reciprocal and make the exponent positive. Alternatively, you could just put in that expression to a calculator and it'll do the work for you.
 one year ago

SmoothMathBest ResponseYou've already chosen the best response.1
Not quite. \[(\frac{1}{e})^{0.15}\]
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
so it would be \[(1  ({1 \over e})^{0.15})\]
 one year ago

lilg132Best ResponseYou've already chosen the best response.0
thanks alot mate appreciate your great help
 one year ago
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