How to do 189th question?

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1 Answer
Mar 30, 2018

Answer:

(2)

Explanation:

A force

#P = (0,0,-m g)#

shall be decomposed as the sum

#P = F_1+F_2+F_3# with

#F_1 = f(cos30^@,sin30^@,sin30^@)#
#F_2 = f(-cos30^@,sin30^@,sin30^@)#
#F_3 = f(0,-1,sin30^@)#

then with the third component

#-mg = 3fsin 30^@# hence

#absf = (mg)/(3sin30^@) = 2/3mg#