A projectile is thrown in the upward direction making an angle of $60^o$ with the horizontal direction with a velocity of $150\, ms^{-1}$. Then the time after which its inclination with the horizontal is $45^o$ is
$15\,\left( {\sqrt 3 - 1} \right)\,s$
$15\,\left( {\sqrt 3 + 1} \right)\,s$
$7.5\,\left( {\sqrt 3 - 1} \right)\,s$
$7.5\,\left( {\sqrt 3 + 1} \right)\,s$
A small boy is throwing a ball towards a wall $6 \,m$ in front of him. He releases the ball at a height of $1.4 \,m$ from the ground. The ball bounces from the wall at a height of $3 \,m$, rebounds from the ground and reaches the boy's hand exactly at the point of release. Assuming the two bounces (one from the wall and the other from the ground) to be perfectly elastic, .......... $m$ far ahead of the boy did the ball bounce from the ground
A boy throws a ball with a velocity $u$ at an angle $\theta$ with the horizontal. At the same instant he starts running with uniform velocity to catch the ball before if hits the ground. To achieve this he should run with a velocity of
The greatest height to which a man can throw a stone is $h$. The greatest distance to which he can throw it, will be
The angle of projection at which the horizontal range and maximum height of projectile are equal is
Two particles in same vertical plane are thrown to strike at same time. One from ground and other from height $h$ vertically above it. Ground particle is thrown obliquly and it achives a maximum height $H$. The second particle is thrown horizontally with same speed. What can be maximum $h$ so that two particles strike in air.