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Grade 11Mechanics

A boy is hanging from the horizontal branch of atree. the tension in the arms will be maximum when the angle between the arms is

Profile image of syed ameerunnisa
8 Years agoGrade 11
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1 Answer

Profile image of Arun
ApprovedApproved Tutor Answer8 Years ago
 
The resultant of tensions in the arm must be equal to weight F (= mg)
Hence
F² = P² +P² + 2P² cos @
F² = 2P²( 1+ cos@)
P² = F²/2(1+cos @)
P is max when (1+ cos@ ) is min
 Cos @ = -1
@ = 180 ° is not possible
Hence cos @ = -1/2
Hence
@ = 120 °