J johnle95 New Member Joined Mar 14, 2013 Messages 25 Gender Undisclosed HSC N/A Mar 16, 2013 #1 hi guys how would u do the questions attached? Last edited: Mar 16, 2013
P Parvee (╯°□°）╯︵ ┻━┻ Joined Apr 4, 2011 Messages 1,077 Gender Female HSC 2012 Mar 16, 2013 #2 10. When t=0, N=3000 3000=1800+Ae^0 A=1200 When t=3, N=3400 3400=1800+1200e^3k 1200e^3k=1600 3k=ln(16/12) k=[ln(16/12)]/3 k=0.09589..... a) N=1800+1200e^5k =3738 b) 8000=1800+1200e^kt 6200=1200e^kt e^kt=6200/1200 kt= ln(6200/1200) t= [ln(6200/1200)]/k t=17.13 yrs
10. When t=0, N=3000 3000=1800+Ae^0 A=1200 When t=3, N=3400 3400=1800+1200e^3k 1200e^3k=1600 3k=ln(16/12) k=[ln(16/12)]/3 k=0.09589..... a) N=1800+1200e^5k =3738 b) 8000=1800+1200e^kt 6200=1200e^kt e^kt=6200/1200 kt= ln(6200/1200) t= [ln(6200/1200)]/k t=17.13 yrs
P Parvee (╯°□°）╯︵ ┻━┻ Joined Apr 4, 2011 Messages 1,077 Gender Female HSC 2012 Mar 16, 2013 #3 8. a) dv/dt=-kAe^-kt =-k(P+Ae^-kt +P) =-k(v-P) b) 0=500+Ae^0 A=-500 21=500-500e^5k -479=-500e^5k e^5k=479/500 5k= ln(479/500) k= [ln(479/500)]/5 = -8.58x10^-3 c) v=500-500e^20k = 78.85ms^-1 d) As t --> infinity e^kt --> 0 Therefore v=500 - 500(0) v=500ms^-1
8. a) dv/dt=-kAe^-kt =-k(P+Ae^-kt +P) =-k(v-P) b) 0=500+Ae^0 A=-500 21=500-500e^5k -479=-500e^5k e^5k=479/500 5k= ln(479/500) k= [ln(479/500)]/5 = -8.58x10^-3 c) v=500-500e^20k = 78.85ms^-1 d) As t --> infinity e^kt --> 0 Therefore v=500 - 500(0) v=500ms^-1
P Parvee (╯°□°）╯︵ ┻━┻ Joined Apr 4, 2011 Messages 1,077 Gender Female HSC 2012 Mar 16, 2013 #4 I'm not gonna do the rest.... All these questions basically have the same process, so you should be able to do the other ones.
I'm not gonna do the rest.... All these questions basically have the same process, so you should be able to do the other ones.
J johnle95 New Member Joined Mar 14, 2013 Messages 25 Gender Undisclosed HSC N/A Mar 16, 2013 #5 Parvee said: I'm not gonna do the rest.... All these questions basically have the same process, so you should be able to do the other ones. Click to expand... i just have trouble interpreting the questions could u please please do the rest?
Parvee said: I'm not gonna do the rest.... All these questions basically have the same process, so you should be able to do the other ones. Click to expand... i just have trouble interpreting the questions could u please please do the rest?
