The ceiling of a long hall is $25\; m$ high. What is the maximum horizontal distance that a ball thrown with a speed of $40\; m/ s$ can go without hitting the ceiling of the hall ?
Speed of the ball, $u=40\, m / s$ Maximum height, $h=25 \,m$
In projectile motion, the maximum height reached by a body projected at an angle $\theta,$ is given by the relation:
$h=\frac{u^{2} \sin ^{2} \theta}{2 g}$
$25=\frac{(40)^{2} \sin ^{2} \theta}{2 \times 9.8}$
$\sin ^{2} \theta=0.30625$
$\sin \theta=0.5534: . \theta=\sin ^{-1}(0.5534)=33.60^{\circ}$
Horizontal Range $R=\frac{u^{2} \sin 2 \theta}{g}$
$=\frac{(40)^{2} \times \sin 2 \times 33.60}{9.8}$
$=\frac{1600 \times \sin 67.2}{9.8}$
$=\frac{1600 \times 0.922}{9.8}=150.53\, m$
A cricket fielder can throw the cricket ball with a speed $v_{0} .$ If he throws the ball while running with speed $u$ at an angle $\theta$ to the horizontal, find
$(a)$ the effective angle to the horizontal at which the ball is projected in air as seen by a spectator
$(b)$ what will be time of flight?
$(c)$ what is the distance (horizontal range) from the point of projection at which the ball will land ?
$(d)$ find $\theta$ at which he should throw the ball that would maximise the horizontal range as found in $(iii)$.
$(e)$ how does $\theta $ for maximum range change if $u > u_0$. $u =u_0$ $u < v_0$ ?
$(f)$ how does $\theta $ in $(v)$ compare with that for $u=0$ $($ i.e., $45^{o})$ ?
A ball is projected vertically upwards with a certain initial speed. Another ball of the same mass is projected with the same speed at an angle of $30^o$ with the horizontal. At the highest point, the ratio of their potential energies is
The horizontal range of a projectile is $4\sqrt 3 $ times its maximum height. Its angle of projection will be ......... $^o$
A person is standing on an open car moving with a constant velocity of $30\,\,m/s$ on a straight horizontal road. The man throws a ball in the vertically upward direction and it returns to the person after the car has moved $240\,\,m.$ The speed and the angle of projection
A bullet is dropped from the same height when another bullet is fired horizontally. They will hit the ground