In the given figure the blocks A, B and C weigh \( 4 \, \text{kg} \), \( 6 \, \text{kg} \) and \( 8 \, \text{kg} \) respectively. The co-efficient of sliding friction between any two surfaces is \( 0.5 \). The force \( F \) required to slide the block C with constant speed is ______ \( \text{N} \).
(Use \( g = 10 \, \text{m/s}^2 \))
