Hey there Sign in to join this conversationNew here? Join for free

Moment's question

Announcements Posted on
Study Help needs new mods! 14-04-2014
Post on TSR and win a prize! Find out more... 10-04-2014
    • Thread Starter
    • 3 followers
    Offline

    ReputationRep:
    Determine the moment of the 60N force about point A on the perimeter of the disk by determining the lever arm of the force:
    (Note, the lever arm is the perpendicular distance from the line of action of the force to the point where the moment is to be taken about)

    • Thread Starter
    • 3 followers
    Offline

    ReputationRep:
    Any ideas?

    I cannot calculate the perpendicular distance from the line of action of the force to the point A.
    I have tried calculating the lengths of the other lines that would add up using pythagoras theorem to obtain the perpendicular, but I can't find the necessary angles.
    • 3 followers
    Offline

    ReputationRep:
    (Original post by sulexk)
    Any ideas?

    I cannot calculate the perpendicular distance from the line of action of the force to the point A.
    I have tried calculating the lengths of the other lines that would add up using pythagoras theorem to obtain the perpendicular, but I can't find the necessary angles.
    Calculate AC by the cosine rule. The angle AOC is 165. AO=OC=250
    The angle between AC and the force is 60 (75-15).
    The perpendicular distance (d) d=AC*sin 60
    Click image for larger version. 

Name:	moment.png 
Views:	17 
Size:	16.2 KB 
ID:	139918
    • Thread Starter
    • 3 followers
    Offline

    ReputationRep:
    (Original post by ztibor)
    Calculate AC by the cosine rule. The angle AOC is 165. AO=OC=250
    The angle between AC and the force is 60 (75-15).
    The perpendicular distance (d) d=AC*sin 60
    Click image for larger version. 

Name:	moment.png 
Views:	17 
Size:	16.2 KB 
ID:	139918
    Thank you very much

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?

    this is what you'll be called on TSR

  2. this can't be left blank
    this email is already registered. Forgotten your password?

    never shared and never spammed

  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By completing the slider below you agree to The Student Room's terms & conditions and site rules

  2. Slide the button to the right to create your account

    Slide to join now Processing…

    You don't slide that way? No problem.

Updated: April 5, 2012
Article updates
Reputation gems:
You get these gems as you gain rep from other members for making good contributions and giving helpful advice.