Qualification > Math
Additional Math Help HERE ONLY...!
jellybeans:
--- Quote from: cooldude on June 02, 2010, 05:23:01 pm ---actually the q wont mention that the displacement is 7.5m u have to find this by calculation, ill show u what i mean, at t=5 sec the displacement is +7.5m
x=0.7t^2-0.1t^3+0.5t
when t=5, x=+7.5m
then the displacement is 0 at-->
0=0.7t^2-0.1t^3+0.5t
at t=7.65 the displacement is again 0 proving that the particle did travel +7.5m in the positive direction between 0 and 5, and then between 0 and 7.65 it again travels back to the origin a further 7.5m, the dist travelled=15m
now for the last 2.35 sec, u can find the displacement, u can integrate between 10 and 7.65 in the displacement, we get -25m, proving that the total dist is 7.5+7.5+25=40 , this should clear things up, if u need more explanation ill be happy to give it
--- End quote ---
so you have to find out t when displacement = 0 ? ..which will then tell you that it returns to its origin.. and so .. its 7.5 x 2 for going there and back?
:o
J.Darren:
ln y = ln a + x ln b
Y = ln y
X = x
m = ln b
c = ln a
ln y = ln A + k ln x
Y = ln y
X = ln x
m = k
c = ln a
jellybeans:
--- Quote from: J.Darren on June 02, 2010, 05:33:33 pm ---ln y = ln a + x ln b
Y = ln y
X = x
m = ln b
c = ln a
ln y = ln A + k ln x
Y = ln y
X = ln x
m = k
c = ln a
--- End quote ---
wait sorry.. is that the 3rd bit? :O
cuz for the first two i used logs instead of ln , ... :-\
anyways; for iii) i did:
px+qy=xy
xy-qy = px
(x-q)y = px
y = px / (x-q)
lol .. and yh. thats how far i got for 9iii) Xb
cooldude:
--- Quote from: jellybeans on June 02, 2010, 05:31:14 pm ---so you have to find out t when displacement = 0 ? ..which will then tell you that it returns to its origin.. and so .. its 7.5 x 2?
:o
--- End quote ---
yeah, if u get more than one value it basically tells u that the particle passes the origin at more than one point, i.e. it moves first in the positive direction and then in the negative direction, and then u have to find the distance travelled in the positive and the negative direction, and theres also one more way to find if the particle goes in the positive direction, if u find the maximum displacement and it comes to a value not equal to ur final displacement, i.e. in this q if the maximum displacement is not -25m then u get to knw that the particle has travelled in the positive direction also, for example in this u get the maximum displacement at t=5, i.e. x=7.5m, thus u get to knw that the particle has also travelled in the positive direction and u can take the movement in the positive direction into account
J.Darren:
--- Quote from: jellybeans on June 02, 2010, 05:35:23 pm ---wait sorry.. is that the 3rd bit? :O
cuz for the first two i used logs instead of ln , ... :-\
px+qy=xy
xy-qy = px
(x-q)y = px
y = px / (x-q)
lol .. and yh. thats how far i got for 9iii) Xb
--- End quote ---
x - q = px / y
(x - q) / x = (px / y) * (1 / x)
(x - q) / x = p / y
1 - q / x = p / y
y = p / (1 - q / x)
would it works ?
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version