Question

tell the force on 2m due to 1m​

Answer 1

The question is quite easy and so is the answer

However

When you draw FBD of block of 2 kg mass There are 3 forces acting on it

(1) N1 - normal force in downward direction due to the weight 3kg and 4 kg simultaneously which is equal to (3+4)*10 N = 70 N

(2) N2 - normal force in upward direction due to block of mass 1 kg which will be calculated later

(3) mg = gravitational force by earth = 2*10 N = 20 N

Since 2 kg bolck is in equilibrium in vertical direction

We can say sum of all the forces on it in vertical direction is zero

So

N1 + N2 + W = 0

N1 = - 70 N (taking upward direction as positive and downward direction as negative )

mg = - 20 N

So

( - 70N ) + ( - 20N ) + N2 = 0

N2 = + 90 N

So N2 is the answer