A boy playing on the roof of a $10\, m$ high building throws a ball with a speed of $10\,m/s$ at an angle of $30^o$ with the horizontal. How far from the throwing point will the ball be at the height of $10\, m$ from the ground ?  $\left[ {g = 10\,m/{s^2},\sin \,{{30}^o} = \frac{1}{2},\cos \,{{30}^o} = \frac{{\sqrt 3 }}{2}} \right]$

  • A

    $5\sqrt 5 $

  • B

    $6$

  • C

    $3$

  • D

    $5\sqrt 3 $

Similar Questions

A shell fired from the base of a mountain just clears it. If $\alpha$ is the angle of projection then the angular elevation of the summit $\beta$ is

      Column $-I$

    Angle of projection

    Column $-II$
  $A.$ $\theta \, = \,{45^o}$   $1.$ $\frac{{{K_h}}}{{{K_i}}} = \frac{1}{4}$
  $B.$ $\theta \, = \,{60^o}$   $2.$ $\frac{{g{T^2}}}{R} = 8$
  $C.$ $\theta \, = \,{30^o}$   $3.$ $\frac{R}{H} = 4\sqrt 3 $
  $D.$ $\theta \, = \,{\tan ^{ - 1}}\,4$   $4.$ $\frac{R}{H} = 4$

$K_i :$ initial kinetic energy

$K_h :$ kinetic energy at the highest point

Galileo writes that for angles of projection of a projectile at angles $(45 + \theta )$ and $(45 - \theta )$, the horizontal ranges described by the projectile are in the ratio of (if $\theta \le 45)$

A projectile crosses two walls of equal height $H$ symmetrically as shown  The time of flight $T$ is given by  ........ $\sec$

Two projectiles $A$ and $B$ are thrown with initial velocities of $40\,m / s$ and $60\,m / s$ at angles $30^{\circ}$ and $60^{\circ}$ with the horizontal respectively. The ratio of their ranges respectively is $\left( g =10\,m / s ^2\right)$

  • [JEE MAIN 2023]