Three blocks A, B, and C of masses `3M, 2M`, and M are suspended vertically with the help of spring PQ and TU, and a string RS as shown in fig. If the acceleration of blocks A, B and C is `a_(1), a_(2)` and `a_(3)` , respectively, then

The value of acceleration `a_(1)` at the moment string RS is cut is

Options

A. a. g, downward
B. g, upward
C. More than g, downwards
D. Zero

Answer

B

Explanation

Force in spring can't change abruptly whereas tension in string can change.
Tension in PQ is 6 Mg before cutting RS.
After cutting RS, `a_(1)=(6Mg-3Mg)/(3M)=g`