Q.

Two blocks of masses 10 kg and 20 kg are connected by a massless string and are placed on a smooth horizontal surface as shown in the figure. If a force F = 600 N is applied to 10 kg block, then the tension in the string is

1 100 N  
2 200 N  
3 300 N  
4 400 N  

Ans.

(4)

Here, m1=10 kg, m2=20 kg, F=600 N

Let T be tension of the string and a be common acceleration of the system.

∴  a=Fm1+m2=600 N10 kg+20 kg=60030 m s-2=20 m s-2

When a force F is applied on 10 kg block, then the tension in the string is

T=m2a=(20 kg)(20 m s-2)=400 N