A 'T' shaped object with dimensions shown in the figure, is lying on a smooth floor. A force F is applied at the point P parallel to AB, such that the object has only the translational motion without rotation. Find the location of P with respect to C
(A)32ℓ
(B)23ℓ
(C)34ℓ✓ Correct
(D)ℓ
Answer: (C)
Solution
For the object to slide without turning, the applied force must pass through its centre of mass, so P must lie at the centre of mass measured from C. Treating the 'T' as the two rods shown and taking moments of their masses about C with the lengths marked in the figure, the mass-weighted mean position works out to 34ℓ from C. A force applied there has its line of action through the centre of mass, giving pure translation with no rotation.
JEE Main · 2005 · 08 May 2005 · Offline · Single correct option