Two paper screens $A$ and $B$ are separated by distance $100 \,m$. A bullet penetrates $A$ and $B$, at points $P$ and $Q$ respectively, where $Q$ is $10 \,cm$ below $P$. If bullet is travelling horizontally at the time of hitting $A$, the velocity of bullet at $A$ is nearly .......... $m / s$
$100$
$200$
$600$
$700$
Two balls of mass $M$ and $2 \,M$ are thrown horizontally with the same initial velocity $v_{0}$ from top of a tall tower and experience a drag force of $-k v(k > 0)$, where $v$ is the instantaneous velocity. then,
A slide with a frictionless curved surface, which becomes horizontal at its lower end,, is fixed on the terrace of a building of height $3 h$ from the ground, as shown in the figure. A spherical ball of mass $\mathrm{m}$ is released on the slide from rest at a height $h$ from the top of the terrace. The ball leaves the slide with a velocity $\vec{u}_0=u_0 \hat{x}$ and falls on the ground at a distance $d$ from the building making an angle $\theta$ with the horizontal. It bounces off with a velocity $\overrightarrow{\mathrm{v}}$ and reaches a maximum height $h_l$. The acceleration due to gravity is $g$ and the coefficient of restitution of the ground is $1 / \sqrt{3}$. Which of the following statement($s$) is(are) correct?
($AV$) $\vec{u}_0=\sqrt{2 g h} \hat{x}$ ($B$) $\vec{v}=\sqrt{2 g h}(\hat{x}-\hat{z})$ ($C$) $\theta=60^{\circ}$ ($D$) $d / h_1=2 \sqrt{3}$
In the figure shown, velocity of the particle at $P \,(g = 10\,m/s^2)$
A plane is flying horizontally at $98\, m/s$ and releases an object which reaches the ground in $10 \sec$. The angle made by object while hitting the ground is ......... $^o$
A ball is projected from the ground at an angle of $45^{\circ}$ with the horizontal surface. It reaches a maximum height of $120 m$ and returns to the ground. Upon hitting the ground for the first time, it loses half of its kinetic energy. Immediately after the bounce, the velocity of the ball makes an angle of $30^{\circ}$ with the horizontal surface. The maximum height it reaches after the bounce, in metres, is. . . . .