Three blocks \( M_1, M_2, M_3 \) having masses \( 4 \, \text{kg} \), \( 6 \, \text{kg} \) and \( 10 \, \text{kg} \) respectively are hanging from a smooth pully using rope \( 1 \), \( 2 \) and \( 3 \) as shown in figure. The tension in the rope \( 1 \), \( T_1 \) when they are moving upward with acceleration of \( 2 \, \text{m s}^{-2} \) is __________ \( \text{N} \) (if \( g = 10 \, \text{m/s}^2 \)).
