
Algebra PreAlgebra and Basic Algebra Math Forum 
 LinkBack  Thread Tools  Display Modes 
May 4th, 2014, 03:31 PM  #1 
Newbie Joined: May 2014 From: Lancashire England Posts: 1 Thanks: 0  Analytical Methods  Logartithms / Obtaining Expressions
Hello all! I am new here, and in the UK doing a course on engineering. I have been really struggling with 1 assignment, which i require in for tuesday. A picture of the questions is here (may be 90 degree angle, uploaded funny): For a) and b) on here I have worked out A) 15.34, and B) 47.925. Apart from the 2 I answered above, I am totally confused by these 
May 4th, 2014, 07:07 PM  #2 
Math Team Joined: Dec 2013 From: Colombia Posts: 7,600 Thanks: 2588 Math Focus: Mainly analysis and algebra 
c) We just take logarithms of both sides, so $\log{y} = \log{kn^w} = \log{k} + w\log{n}$ The rest of that page should be straightforward. Task 4 a) $R\sin{(wt + a)} = R\left(\sin{wt}\cos{a} + \cos{wt}\sin{a}\right)$. Comparing coefficients of $\sin{wt}$ gives you one equation, the coefficients of $\cos{wt}$ give you a second. You can then solve these simultaneous equations for $R$ and $a$. b) Period $T = \frac{1}{f}$ and angular velocity $w = \frac{2\pi}{T}$ (you can work these equations out simply by comparing the units). d) The equation will give an infinite number of solutions because the current is periodic. They want the one where $0 \le t \le 10 \text{ms}$. Task 5 a) Plug the values in and see what comes out. b) Acceleration is rate of change of velocity, or how velocity changes with respect to time. Therefore we differentiate the velocity with respect to time. Then, Newton's Second Law $F = ma$ applies. Is the force in the same direction as the velocity, or against it? c) Put $a = 0$ and solve for $t$. d) Velocity is the rate of change of position. So we must integrate (with respect to time) the expression for velocity to obtain an expression for the distance travelled. 

Tags 
analytical, expressions, logartithms, methods, obtaining 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
obtaining stationary values  kgiboin  Calculus  2  March 24th, 2013 06:15 PM 
The probability of obtaining 3 and a tail  Chikis  Advanced Statistics  56  July 30th, 2012 04:43 AM 
Obtaining a formula  senogles100  Calculus  5  May 1st, 2012 02:25 AM 
Analytical methods  finfanillo  Linear Algebra  0  March 21st, 2012 11:14 PM 
Obtaining a formula  senogles100  Algebra  3  December 31st, 1969 04:00 PM 