Question

Two objects 7kg and 5kg are attached to an inextensible string which passes over a frictionless pulley such that 5 kg is moving over a frictionless horizontal surface and mass 7kg is moving vertically downwards. Find acceleration in the system and tension in the string.​

Answer 1

Answer:

The equation of motion for mass M

1

: M 1

a=T−M 1g ...(1)

and for mass M

2: M 2

a=M

2g−T ....(2)

(1)+(2)⇒a(M 1 +M 2 )=(M 2−M 1)g

or a= M 1+M 2

(M 2 −M 1)g= 7+12(12−7)(10)

=(50/19)m/s

From (1), T=M 1(a+g)=7(50/19+10)=88.42N