$A$ ball is thrown vertically upwards from the top of a tower with a velocity $u$. This ball reaches the ground level with a velocity $4u$. The height of the tower is:

Two balls $A$ and $B$ are thrown with the same velocity $u$ from the top of a tower. Ball $A$ is thrown vertically upwards and ball $B$ is thrown vertically downwards. Choose the correct statement.

Which graph best shows the velocity-time graph for an object launched vertically into the air when air resistance is given by $|D| = bv$? The dashed line shows the velocity graph if there were no air resistance.

$A$ body thrown vertically upwards from the ground reaches a maximum height $H$. The ratio of the velocities of the body at heights $\frac{3H}{4}$ and $\frac{8H}{9}$ from the ground is

What is the speed-time graph for a ball thrown vertically upwards? (Neglect air resistance)

$A$ body projected vertically upwards with a certain speed from the top of a tower reaches the ground in $t_1$. If it is projected vertically downwards from the same point with the same speed,it reaches the ground in $t_2$. Time required to reach the ground,if it is dropped from the top of the tower,is: