From the top of a tower of height $40\, m$, a ball is projected upwards with a speed of $20\, m/s$ at an angle $30^o$ to the horizontal. The ball will hit the ground in time ......... $\sec$ (Take $g = 10\, m/s^2$)

A body is thrown with a velocity of $9.8 \,m/s$ making an angle of $30^o$ with the horizontal. It will hit the ground after a time ....... $\sec$

A projectile projected at an angle ${30^o}$ from the horizontal has a range $2\upsilon ,\,\sqrt 2 \upsilon \,\,{\rm{ and}}\,{\rm{zero}}$. If the angle of projection at the same initial velocity be ${60^o}$, then the range will be

A cricketer can throw a ball to a maximum horizontal distance of $100 \,m$. With the same effort, he throws the ball vertically upwards. The maximum height attained by the ball is  ......... $m$

A ball of mass $m$ is thrown vertically upwards. Another ball of mass $2m$ is thrown at an angle $\theta $ with the vertical. Both of them stay in air for same period of time. The heights attained by the two balls are in the ratio of

If $R$ and $H$ represent the horizontal range and the maximum height achieved by a projectile then which of the relation exists?