Question

Two identical blocks of 10 kg each are sitting on incline angle 30

Answer 1

it would be better if i make a block diagram of the problem but it is not possible for me but still i will try to make you understand. first of all 1 kg.wt means a force that is required to accelerate a mass of 1 kg with an acceleration of approx 9.8 m/s2.
here the block is just going to slide down the wedge..so friction force needed to stop the block is mg*sin30.
since, mass = 10kg, force required = 10*g*sin30 newton
= 5*g newton
= 5 kg.wt …............... {since 1 kg.wt = 1*g newton, where g = 9.8 m/s2 }