Answer to Question #42019 in Mechanics | Relativity for Tanya

Question

Hey
And its,a physics ques
From laws of motion-motion in connected bodies

There was a,ques of 2 bodies suspended from a pully m1>m2 with acceleration a
Find a
And tension

Ans was a=(m1-m2)g/(m1+m2)

And T=2m1m2g/(m1+m2)



For mass m1
T=m1g-m1a (i)

For m2
T =m2a+m2g

My doubt
Why acc is taken in opp dir.?
Since in m1 acc is downward thus eqn should be
For mass m1
T=m1g+m1a (i)

and for m2 acc is upward
T =m2g-m2a

Then f=ma is taken opp
In direction
When it is along the direction of mg in m1 case and along t in m2 case