Recent content by wozzers

okay now i have differentiated it with respect to r i get 2V2r/R^2) or -(4Vr/R^2) thanks again i was then required to use the wall shear stress to determine the frictional force but it is very straight forward from there

r=R and its (r/R)^2

Homework Statement having problems differentiating Homework Equations Tw ( wall shear stress)= -U(viscosity)*du/dr been given u as 2V(1-(r/r)^2) The Attempt at a Solution i substituted u in and got d/dr (2V(1-(r/r)^2) i tried to multiply out the minus sign and 2V and got...

i've looked in the book i am struggling to find these type of problems in the book do you know where exactly in the book these problems are?

thank you all for your help i finally worked it out, i have a better understanding using the substitution method hallsofivy i still need to practice a few more problems to be confident in my ability to solve the type of DE using the Intial condition i got y= sqrt (6x+4) -2x-1 quite happy...

i will take a look at the book ackbeet as i know this is something i am going to have to apply consistently to completely comprehend this type of problem

okay i took the derivative of y+2x+1 and got 3dydx is that right or a little off with the dydx from there i am lost once again

at the moment none i thought about doing something with the y+2x and using a u substitution but noticed the signs were different so i am just lost currently and i wasn't sure if that is even applicable in this situation

i am having issues solving an ODE it is given as y'= (1-2y-4x)/(1+y+2x) I've been told to find the particular solution when y(0)=1 please help

yes i thought that was the way but i just don't seem to get the answer my tutor has given i can get one of the numbers the 3e^2t but i can't find 3cosht and 4sinht

{6s^2 - 2s - 11}/(s-2)(s^2-1)}. the problem i have is breaking it down to its partial fractions

i put in the wrong transform for the first one it is 6s^2-2s-11/(s-2)(s^2-1)

Homework Statement find the partial fractions and thus the inverse of the following 6s^2-2s-11/(s-1)(s^2-1) and 7s^2+8s+16/(s+2)(s^2+3) Homework Equations answer tutor gave for the fist one was 3e^2t + 3cosht + sinht and second was 4e^-2t+3cos sqrt3t+ 2/sqrt3 sin sqrt3 The...