question_answer

Two bodies A and B of masses 10 kg and 15 kg respectively kept on a smooth, horizontal surface are tied to the ends of a light string. If T represents the tension in the string when a horizontal force F = 500 N is applied to A (as shown in figure 1) and T be the tension when it is applied to B (figure 2), then which of the following is true?

A)  \[T=T=500\,N\]

B)  \[T=T=250\,N\]

C)  \[T=200\,N,T=300N\]

D)  \[T=300\,N,T=200N\]

Correct Answer: D

Solution :

                 For the first case acceleration \[a=\frac{F}{{{m}_{1}}+{{m}_{2}}}\]                 is same in both the cases as \[{{F}_{1}}={{F}_{2}}\] masses of the blocks are same \[a=20\,m{{s}^{-2}}\] Now for first case the force is applied on block A \[\therefore \]  \[T=500-10\times 20=300\,N\] Similarly, for block 2 the force is applied on block B \[\therefore \]  \[T=500-15\times 20=200\,N\]