abcb_007

horizontal component of R balances T cos 12 (points to the right).

Take moments about where T acts upon.
clockwise moment by L = (40)(0.24) = 9.6 N m
anti-clockwise moment by W = (520)(0.03) = 15.6 N m

This means that the vertical component of R has to produce a clockwise moment of (15.6 - 9.6) = 6 N m about where T acts upon.  Hence the vertical component of R point upwards.

[ 本帖最後由 abcb_007 於 2016-1-23 03:29 PM 編輯 ]