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Two bodies of masses m1 and m2 are connected by a light string which passes over a frictionless, massless pulley. If the pulley is moving with uniform acceleration g/2, then tension in the string will be?
Verified Answer
Two bodies of masses m1 and m2 are connected by a light string which p...
Let   m2 > m1.

Consider the masses m1 and m2, with forces Tension T in the string upwards and their weights downwards, acting on them.  Both of these masses are moving with same acceleration a up (m1) or down (m2 as m2>m1), as the string is tight and has a uniform tension all along its length. This explanation is valid in the frame of reference of moving pulley with an acceleration g/2 upwards.

In the frame of reference of pulley, with an acceleration g/2 upwards, the two masses are having acceleration a and -a.  To balance forces in this non-inertial frame, we need to add a fictitious force of  m1 g/2 downwards on m1 and -m2 g/2 downwards on m2.  Then we write free body diagrams and apply Newtons' laws.

           T - (m1 g +m1 g/2) = m1 a      =>    T - 3 m1*g/2 = m1 a
           (m2 g +m2 g/2) - T = m2 a      =>    3 m2*g/2 - T = m2 a

   Add the two equations to get

                   a = (3g/2) * (m2 - m1) / (m1 + m2)
    then,
                   T = 3m1 g/2 + m1 a  =  3 m1 m2  g  / (m1 + m2)

In the inertial frame wrt  a stationary person, 

   acceleration of the mass m1 = a1 = a + g / 2 upwards
               a1 = g * (2 m2 - m1) / (m1 + m2)  upwards

   acceleration of mass m2 = a2 = a - g / 2  downwards
               a2 =  g * (m2 - 2 m1) / (m1 + m2)  downwards

You can verify,  by putting, m1=m2,  then a = 0 in the frame  of pulley, as both weights are same.  But in the inertial frame, a1 = g/2,  and  a2 = -g/2 downwards or,  g/2 upwards.
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Most Upvoted Answer
Two bodies of masses m1 and m2 are connected by a light string which p...
Introduction:
In this scenario, we have two bodies of masses m1 and m2 connected by a light string passing over a frictionless and massless pulley. The pulley is moving with uniform acceleration g/2. We need to determine the tension in the string.

Analysis:
To find the tension in the string, we can consider the forces acting on each body separately.

Body 1:
Let's consider body 1 with mass m1. The forces acting on this body are:
- The weight force (mg1) acting downwards.
- The tension force (T) acting upwards.

Since the pulley is moving with uniform acceleration g/2, the net force acting on body 1 will be the difference between the tension force and the weight force:

Net force on body 1 = T - mg1

According to Newton's second law, the net force is given by:

Net force on body 1 = m1 * acceleration

Body 2:
Now let's consider body 2 with mass m2. The forces acting on this body are:
- The weight force (mg2) acting downwards.
- The tension force (T) acting downwards.

The net force acting on body 2 will be the sum of the tension force and the weight force:

Net force on body 2 = T + mg2

According to Newton's second law, the net force is given by:

Net force on body 2 = m2 * acceleration

Tension in the string:
Since the tension force in the string is the same for both bodies, we can equate the expressions for the net forces on body 1 and body 2:

T - mg1 = m1 * acceleration (Equation 1)
T + mg2 = m2 * acceleration (Equation 2)

Adding Equation 1 and Equation 2, we get:

2T = (m1 + m2) * acceleration

Dividing both sides by 2, we find:

T = (m1 + m2) * acceleration / 2

Substituting the given acceleration value (g/2), we have:

T = (m1 + m2) * (g/2) / 2

Simplifying further:

T = (m1 + m2) * g / 4

Conclusion:
The tension in the string connecting the two bodies will be (m1 + m2) * g / 4.
Community Answer
Two bodies of masses m1 and m2 are connected by a light string which p...
T=(m1+m2)/2
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Two bodies of masses m1 and m2 are connected by a light string which passes over a frictionless, massless pulley. If the pulley is moving with uniform acceleration g/2, then tension in the string will be?
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