Two identical cubes $A$ and $B$ of same mass $2m$ and side $2d$ are placed one over the other as shown in figure. $B$ is attached to one end of a spring of force constant $k$. The other end of the spring is attached to a wall. The system is resting on a smooth horizontal surface with the spring in the relaxed state. A small object of mass $m$ moving horizontally with speed $v$ at a height $d$ above the horizontal surface hits elastically the block $B$ along the line of their centre of mass. There is no friction between $A$ and $B$ :

(a) find the minimum value of $v$(say $v_0$) such that block $A$ will topple over block $B$

(b) if $v=\frac{v_0}{2}$ find the amplitude of oscillation of block spring system.

 

A $\sqrt{34} \mathrm{m}$ long ladder weighing $10 \mathrm{kg}$ leans on a frictionless wall. Its feet rest on the floor $3 \mathrm{m}$ away from the wall as shown in the figure. If $F_f$ and $F_w$ are the reaction forces of the floor and the wall, then ratio of $\frac{F_w}{F_f}$ will be :
(Use $g=10 \mathrm{m} {\mathrm{s}}^{-2}$.)

Shown in the figure is rigid and uniform one meter long rod $\mathrm{AB}$ held in horizontal position by two strings tied to its ends and attached to the ceiling. The rod is off mass $\text{'}\mathrm{m}\text{'}$ and has another weight of mass $2 \mathrm{m}$ hung at a distance of $75 \mathrm{cm}$ from $\mathrm{A}$. The tension in the string at $\mathrm{A}$ is:

One end of a horizontal uniform beam of weight $W$ and length $L$ is hinged on a vertical wall at point $O$ and its other end is supported by a light inextensible rope. The other end of the rope is fixed at point $Q$, at a height $L$ above the hinge at point $O$. A block of weight $\alpha W$ is attached at the point $P$ of the beam, as shown in the figure (not to scale). The rope can sustain a maximum tension of  $\left(2\sqrt{2}\right)W$. Which of the following statement(s) is(are) correct?

A uniform rod of length $200 \mathrm{cm}$ and mass $500 \mathrm{g}$ is balanced on a wedge placed at $40 \mathrm{cm}$ mark. A mass of $2 \mathrm{kg}$ is suspended from the rod at $20 \mathrm{cm}$ and another unknown mass $m$ is suspended from the rod at $160 \mathrm{cm}$ mark as shown in the figure. Find the value of $m$ such that the rod is in equilibrium. $\left.(g=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$

A bead of mass $\mathrm{m}$ stays at point $\mathrm{P}\left(\mathrm{a}, \mathrm{b}\right)$ on a wire bent in the shape of a parabola $y=C{x}^{\mathit{2}}$ and rotating with angular speed $\mathrm{\omega }$ (see figure). The value of $\omega$ is (neglect friction)

A football of radius $R$ is kept on a hole of radius $r(r<R)$ made on a plank kept horizontally. One end of the plank is now lifted so that it gets tilted making an angle $\theta$ from the horizontal as shown in the figure below. The maximum value of $\theta$  so that the football does not start rolling down the plank satisfies (figure is schematic and not drawn to scale)

Consider a uniform cubical box of side a on a rough floor that is to be moved by applying minimum possible force $\mathrm{F}$ at a point $\mathrm{b}$ above its centre of mass (see figure). If the coefficient of friction is $\mu =0.4$ , the maximum possible value of $100\times \frac{\mathrm{b}}{\mathrm{a}}$ for a box not to topple before moving is ________

A bullet of mass m moving with a speed ν hits a stationary block of mass M at the topmost point and gets embedded in it. If friction is sufficient to prevent slipping then the block.

Find the greatest height at which force $F$ may be applied to slide the block without tipping over.

A uniform solid sphere of radius $R$is rolling without sliding on a horizontal surface with a velocity $v_0$. It collides with an obstacle of height$h (< R)$ inelastically. Find the angular speed of the sphere just after the collision.

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$