A Determine the magnitude direction of the moment produced a

A) Determine the magnitude direction of the moment produced at O, taking only the applied forces into consideration. Please state the units.

B) Now assume the system to be in equilibrium, and draw the free body digram incloding BOTH applide forces and reactions. Calculate the values of these reactions.

Solution

A) moment = r x F

for 600N force r = 1i and F = -600j

for 300N force, r = (3i) + (2.5cos45i + 2.5sin45j)

r = 3i + 1.77i + 1.77j = 4.77i + 1.77j and F = 300i

for 500N force, r = 4.77i + 1.77j and F =500 j

moment = [ (1i) x (-600j) ] + [ (4.77i + 1.77j) x 300i] + [ (4.77i + 1.77j) x 500j ]

= ( -600k ) + ( -530.33k) + ( 2385 k ) = 1254.67k N m

Ans(A) = 1254.67 N m

b) to be in equilibrium for the system

a moment = -1254.67 k must be present about point O.