A lift is moving down with an acceleration $a$. A man in the lift drops a ball inside the lift. The acceleration of the ball as observed by the man in the lift and a man standing stationary on the ground are, respectively.

Block $B$ has mass $m$ and is released from rest when it is on top of wedge $A$ which has a mass$3m$. Determine the tension in cord $CD$ needed to hold the wedge from moving while $B$ is sliding down $A$. Neglect function.

Two particles $A$ and $B$ each of mass $m$ are kept stationary by applying a horizontal force $F=mg$ on particle $B$ as shown in the figure. Then

The given figure represents a light inextensible string $ABCDE$ in which $AB=BC=CD=DE$ and to which are attached masses $M, m$ and $M$ at the points $B, C$ and $D$, respectively. The system hangs freely in equilibrium with ends $A$ and $E$ of the string fixed in the same horizontal line. It is given that tan $\tan \alpha =3/4$and $\tan \beta =12/5$. Then the tension in the string $BC$ is