What is the initial velocity of an object falling freely (in $m/s$)?

$A$ ball is dropped from a bridge that is $45 \ m$ above the water. It falls directly into a boat which is moving with constant velocity. The boat is $12 \ m$ away from the point of impact when the ball is dropped. The speed of the boat is (Take $g=10 \ m \ s^{-2}$) (in $m \ s^{-1}$)

$A$ ball is dropped and its displacement versus time graph is as shown (Displacement $x$ from ground and all quantities are positive upwards).
$(a)$ Plot qualitatively velocity versus time graph.
$(b)$ Plot qualitatively acceleration versus time graph.

$A$ player throws a ball upwards with an initial speed of $29.4 \; m s^{-1}$. To what height does the ball rise and after how long (in seconds) does the ball return to the player's hands? (Take $g = 9.8 \; m s^{-2}$ and neglect air resistance).

From the top of a tower,two stones,whose masses are in the ratio $1:2$,are thrown: one straight up with an initial speed $u$ and the second straight down with the same speed $u$. Neglecting air resistance,which of the following is true?

$A$ body is thrown vertically upwards and takes $5 \text{ s}$ to reach maximum height. The distance travelled by the body will be same in