NEET2026PhysicsChapterActual
A uniform horizontal beam of mass 6 kg and length L is hinged to a vertical wall at one end. The other end is supported by a light inextensible wire attached to the same wall, making an angle of 30^ with the beam. A block of mass 9 kg is suspended from the free end of the beam. The horizontal component of the reaction force exerted by the hinge on the beam is (Take g = 10 m/s ^2 )
Options
- A90 3 N
- B120 N
- C120 3 N
- D150 3 N
Correct answer
C. 120 3 N
Step-by-step solution
Let the length of the beam be L . Taking torque about the hinge to be zero for rotational equilibrium: T 30^ L = 60 L 2 + 90 L T 1 2 = 30 + 90 T = 240 N For horizontal equilibrium, the net force in the horizontal direction is zero. The horizontal component of the hinge reaction R_x balances the horizontal component of the tension: R_x = T 30^ R_x = 240 3 2 = 120 3 N Answer: 120 3 N