An elastic string of natural length 3ℓo is cut into two parts so that their natural lengths are 2ℓo and ℓo respectively. They are attached to points P and Q the vertical distance between P and Q being ℓo and the horizontal distance being 12cm. A uniform rod CD=40cm is in equilibrium supported by the string at A and B. If the rod CD is horizontal then the lengths of the parts CA and BD in cms are

Engineering

Physics

Equilibrium

Question

An elastic string of natural length 3ℓ_o is cut into two parts so that their natural lengths are 2ℓ_o and ℓ_o respectively. They are attached to points P and Q the vertical distance between P and Q being ℓ_o and the horizontal distance being 12cm. A uniform rod CD=40cm is in equilibrium supported by the string at A and B. If the rod CD is horizontal then the lengths of the parts CA and BD in cms are

14,14

10,18

16,12

12,16

LiveFree JEE Main Previous Year Online Papers Live Free JEE Advance Previous Year Online Papers

College PredictorLive

Know your College Admission Chances Based on your Rank/Percentile, Category and Home State.

Get your JEE Main Personalised Report with Top Predicted Colleges in JoSA

Ky + $\frac{Ky}{2}$ = mg
𝛕_C = 0
⟹ mg (20 – x) – $\frac{Ky}{2}$ (12) = 0

solving (1) & (2)
⟹ x = 16 cm = AC
OB = 13 cm

Please subscribe our Youtube channel to unlock this solution.