Questions

The interval between object pass the same point is 4 sec.

That means in 2 sec, object reaches the top and in next 2 sec, it again reaches the same point.

By the info given, we can find the velocity of that point by using : v=u+(-gt)

0= u - 10×2

u = 20

Then the velocity at 25m is 20m/sec.

so the initial velocity is

$$\begin{gathered} -v2 = u2 + (-2gh) \\ 400 = u2 - 2x 10 x 25 \\ u2 = 900 \\ => u = 30 m/s \end{gathered}$$

Oenology is the science and study of wine and winemaking. So person who is specialist in that is called as Oenologist.

A Yardstick has three feet used for measuring but no toes.

The name India is originally derived from the name of the river Sindhu (Indus River).