Calculate tensions in chain and chord - Mechanics:

A lamp of mass 1Kg is hung from the ceiling by a chain and is pulled aside by horizontal chord until the chain makes an angle of 60° with ceiling. Find out the tensions in chain and chord.

Sol.: Let,

Tchord  = Tension in chord

Tchain = Tension in chain

W = weight of lamp = 1 × g = 9.81N

Consider point 'C', there are three force acting, so apply lamis theorem at 'C', as C is in equilibrium

T_chord/sin150° = T_chain/sin90° = 9.81/sin120° T_chord = 9.81 × sin150° /sin120°

T_chord = 5.65N     .......ANS

T_chain = 9.81 × sin90° /sin120°

T_chain   = 11.33N                 .......ANS