need help with enigneering mechanics!

IfUWantHateMe SG

if u know how do plssss help!!thankssss
http://img79.imageshack.us/my.php?image=65799954ji0.png

and

http://img141.imageshack.us/my.php?image=70722147sw3.png
thanksss

The Figure shows two forces applied to the light beam AB. If P = 175 N, determine the sum of moments of the forces at A in Nm. You may take clockwise as positive direction.
Inline image Picture1.gif

The Figure shows a light horizontal beam ABC that is loaded by the force P = 100 N. The beam is held in a state of equilibrium by the pin-joint at A and the light cable that passes through a smooth pulley at D. The cable is attached to the beam at locations B and C.

Inline image Eq_Q2.gif

eagle SG

At least copy out the question la...

IfUWantHateMe SG

At least copy out the question la...

hm?i dunno how to paste the question on my post.errrr..the question is all there liao

eagle SG

means copy the words out...

select, copy paste...

IfUWantHateMe SG

means copy the words out...

select, copy paste...

but need see the picture then can do

eagle SG

can copy that picture out also...

next time you do that hor... if not I change here change there read very troublesome

IfUWantHateMe SG

can copy that picture out also...

next time you do that hor... if not I change here change there read very troublesome

copy liao..but my laptop cannot see the pic=(

eagle SG

first question for
http://img79.imageshack.us/my.php?image=65799954ji0.png

clockwise moments = 300 (value of P) x 1.2m = 360Nm

anticlockwise moments = ( 0.8Fb + 1.6Fc ) Nm, where Fc is T, Tension, Fb is upward force at point B

but Fb = T sin 40

Thus, (0.8sin 40 + 1.6) T Nm = 360 Nm
T = 170.3 N

-- change the values accordingly when your question changed values... --

eagle SG

for 2nd question
http://img141.imageshack.us/my.php?image=70722147sw3.png

clockwise moments = 200 * 0.8 Nm = 160 Nm

anti-clockwise moments = P sin 30 * 2m = 156 Nm

Result:
160 - 156 = 4Nm (since clockwise is positive)

-- change the values accordingly when your question changed values... --

Btw, next time save it in jpg or gif or bmp form... This forum cannot display png graphics

IfUWantHateMe SG

for 2nd question
http://img141.imageshack.us/my.php?image=70722147sw3.png

clockwise moments = 200 * 0.8 Nm = 160 Nm

anti-clockwise moments = P sin 30 * 2m = 156 Nm

Result:
160 - 156 = 4Nm (since clockwise is positive)

-- change the values accordingly when your question changed values... --

Btw, next time save it in jpg or gif or bmp form... This forum cannot display png graphics

orhh..hahaha thanks!but the first question u did is wrong lehh..i only get 4 points from the 2nd question u did..

eagle SG

did u change the values, be it force or angle, accordingly?

IfUWantHateMe SG

did u change the values, be it force or angle, accordingly?

i didnt change cus the values were the same

eagle SG

same as the picture, or same as the question in text format...

IfUWantHateMe SG

same as the picture, or same as the question in text format...

its exactly same as the picture..the values angle n everything same de

eagle SG

The question 2 and question 1 u tell me till blur.... Which one is which one now?

2nd question I did is worth 4 points according to the picture what...

IfUWantHateMe SG

The question 2 and question 1 u tell me till blur.... Which one is which one now?

2nd question I did is worth 4 points according to the picture what...

sorry sorry..i meant this question is wrong
http://img79.imageshack.us/my.php?image=65799954ji0.png

eagle SG

so part a is wrong is it?

cuz I just realised I forgot to do part b...

IfUWantHateMe SG

so part a is wrong is it?

cuz I just realised I forgot to do part b...

yep yep. anyway why the 0.8sin40 must plus 1.6 ar?

eagle SG

yep yep. anyway why the 0.8sin40 must plus 1.6 ar?

hmm... was busy whole day.... I try work it out again tmr after my work.... Quite busy these few days... Many things to settle...