Question

Three blocks of masses $2Kg$, $3Kg$ and $4Kg$ are placed on a table as shown in figure. Find the normal force between $3kg$ and $4kg$ block.

Answer 1

$F_{net}=45-9=36N$

$F_{net}=M_{net}{a}_{sys}$

$F_{sys}=\frac{36}{9}=4m/s^2$

$N-9=4\times a$

$N=16+9$

$N=25N$