question_answer

Two blocks \[{{m}_{1}}=5gm\] and\[{{m}_{2}}=\text{10}gm\] are hung vertically over a light frictionless pulley as shown here. What is the acceleration of the masses when they are left free? (Where g is acceleration due to gravity)

A) \[g/3\]  

B) \[g/2\]

C) \[g\]       

D) \[g/5\]

Correct Answer: A

Solution :

[a] Let T be the tension in the string. \therefore 10g-T=10a   ?..(i) T-5g=5a   ?.(ii) Adding (i) and (ii), 5g=15a\Rightarrow a=\frac{g}{3}m/{{s}^{2}}