Two blocks are connected by a string as shown in the diagram. The upper block is hung by another string. A force F applied on the upper string produces an acceleration of `2m//s^(2)` in the upward direction in both the blocks . If T and T' be the tensions in the two parts of the string, then

Options

A. T = 70 8. N and T′ = 47 2. N
B. T = 58.8N and T′ = 47 2. N
C. T = 70 8. N and T′ = 58.8N
D. T = 70 8. N and T′ = 0

Answer

A

Explanation

`a = 2m//s^(2)`
`T - 4g = 4a rArr T = 4 (9.8+2) = 47.2 N`
`T - T(+ 2g) = 2a`
`rArr T = 47.2 + 2 xx 2 + 2 xx 9.8`
` = 70.8 N`