Two masses m1 and m2 are connected by a massless string as . . .

Question : Two masses m1 and m2 are connected by a massless string as shown in figure given below. Find the value of tension in the string if a force of 200 N is applied on (i) m1 and (ii) m2.



Doubt by Shruti 

Solution : 
Here 
m1=30 kg 
m2=50 kg 


F = 200 N
i) When force F=200N is applied to mass m1

Let 'a' be the common acceleration of the system of two blocks. 

F=(m1+m2)a
200=(30+50)a
200=80a
200/80=a
2.5=a
a=2.5 m/s²

Now, 
For body of mass m2, we can write down the equation 

T=m2a
T=50×2.5
T=125 N

ii) When force F=200N is applied to m2

Let again 'a' be the common acceleration of the system of two blocks. 

F=(m1+m2)a
200=(30+50)a
200=80a
200/80=a
2.5=a
a=2.5 m/s²

Now, 
For body of mass m1, we can write down the equation 

T=m1a
T=30×2.5
T=75 N




Similar Question : Two bodies of masses 10kg and 20kg respectively kept on a smooth, horizontal surface are tied to the ends of a light string. A horizontal force F=600N is applied to (i) A, (ii) B along the direction of string. What is the tension in the string in each case?