1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Flatbed truck going round a circular road on an incline

  1. Sep 23, 2014 #1
    1. The problem statement, all variables and given/known data
    The problem statement is in the attachments.


    2. Relevant equations
    F=ma


    3. The attempt at a solution

    I uploaded the solution to the problem. I have had no trouble deriving the first two equations for the summation of forces in the x, n and t directions, however I am having trouble understanding the algebra involved in the solution, specifically where it says, "Solve the first two equations for N and Fn to obtain:", then it lists the equations for N and Fn. I can't figure out how they derived those two equations for N and Fn from the first two equations. flatbed-1.JPG flatbed-1.JPG flatbed-2.JPG
     
  2. jcsd
  3. Sep 23, 2014 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    ... they did exactly what was described - they too the first two equations... these were:
    $$N\cos(10^\circ)-F_{n'}\sin(10^\circ) - mg = 0\\
    F_{n'}\cos(10^\circ) + N\sin(10^\circ) = m\frac{2t^2}{30}$$ ... do you not know how to solve simultaneous equations?
     
  4. Sep 23, 2014 #3
    I know how to solve simultaneous equations, but I am not getting the solution they show in this case. Solving one of the equations for Fn or N and substituting that in the second equation will allow you to eliminate one of the variables. However I am not getting the solutions they provide, I am getting jumbles of sin squared's over cosines and tangents...
     
    Last edited: Sep 23, 2014
  5. Sep 23, 2014 #4

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Please show your working.
     
  6. Sep 23, 2014 #5
    I don't see where my mistake is, but I've ended up with an extra [tex]cos(10)[/tex] in the final answer.
     

    Attached Files:

  7. Sep 23, 2014 #6
    Literally the moment I sent that, I found my mistake. I did not carry the [tex]\frac{mgsin10}{cos10}[/tex] over correctly.
     
  8. Sep 24, 2014 #7

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Well done.
    Note: if you put a backslash before the name of the trig function in LaTeX, it will typeset properly.
    $$\frac{mg\sin\theta}{\cos\theta}=mg\tan\theta$$
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Flatbed truck going round a circular road on an incline
  1. Inclination of roads (Replies: 1)

Loading...