Which of the following statements is not true?

$A$ $1.0 \ kg$ block of wood sits on top of an identical block of wood,which sits on top of a flat level table made of plastic. The coefficient of static friction between the wood surfaces is $\mu_1$,and the coefficient of static friction between the wood and plastic is $\mu_2$. $A$ horizontal force $F$ is applied to the top block only,and this force is increased until the top block starts to move. The bottom block will move with the top block if and only if

$A$ constant force $F$ is applied in the horizontal direction as shown. If the contact force between $M$ and $m$ is $N$ and the contact force between $m$ and $M'$ is $N'$,then:

In the figure,a ladder of mass $m$ is shown leaning against a wall. It is in static equilibrium making an angle $\theta$ with the horizontal floor. The coefficient of friction between the wall and the ladder is $\mu_1$ and that between the floor and the ladder is $\mu_2$. The normal reaction of the wall on the ladder is $N_1$ and that of the floor is $N_2$. If the ladder is about to slip,then

Two blocks of equal masses are connected with a massless spring of spring constant $k = 2500 \,N/m$ and natural length $10 \,cm$, resting on a frictionless horizontal plane. If a constant horizontal force $F = 10 \,N$ is applied as shown in the figure, find the maximum distance between the blocks. (in $cm$)

What is the relationship between $W_1$ and $W_2$?