A uniform light rod AB of length 0.80 m is pivoted at end A so that it can rotate…
PHYSICS · Multi-part · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion
Problem
A uniform light rod AB of length 0.80 m is pivoted at end A so that it can rotate freely in a vertical plane. Two forces act on the rod:
• A downward force of 6 N at end B, perpendicular to the rod.
• An upward force of 4 N at a point C located 0.40 m from A, also perpendicular to the rod.
(i) Draw a neat labelled diagram showing the forces, their lines of action, lever arms and the chosen sign convention for torques about A.
(ii) Calculate the torque produced by each force about the pivot A, taking counter-clockwise torque as positive.
(iii) Determine the net torque about A and state whether the rod tends to rotate clockwise or counter-clockwise.
(iv) Find the net torque of the same two forces about the mid-point of the rod and comment on the difference, if any, between the two results.