Determine the moment of this force

[yosheey]

Homework Statement

The total hip replacement is subjected to a force of F = 120N.
Determine the moment of this force about the neck at A and at the stem B

Homework Equations

M = r X F

The Attempt at a Solution

...

 

[Dr.D]

So, ... where is your work?

 

[tiny-tim]

Welcome to PF!

Hi yosheey ! Welcome to PF!

Show us what you've tried, and where you're stuck, and then we'll know how to help!

 

[jining]

Hi! I am stuck on this problem too, is there anyone that would mind showing me how to do it? My group and I are stuck.

 

[tiny-tim]

welcome to pf!

hi jining! welcome to pf!

(you know what I'm going to say, don't you? …)

Show us what you've tried, and where you're stuck, and then we'll know how to help!

 

[jining]

Hello! Thanks!

Um, so I managed to get the moment about a, but I don't know what to do for b

http://imgur.com/Wx939

 

[tiny-tim]

hello jining!

yes, your moment about A looks fine (you drew that 5° really large … good idea! )

for the moment about B, do it the same way, extending that 15° line until it gets near B …

but of course you need to know how far down B is, and the question doesn't tell you

 

[jining]

Yea... :| that's where I am stuck haha .. any ideas? Thanks for the help.

 

[tiny-tim]

oh i see now, i wasn't looking at the diagram properly …

you can find how far that 150° point is to the right, then use the 10° to find how far down it is from there to B