Questions

Yes, footsteps are what we take more, the more we leave behind. 

We know that 1 year = 365.25 days

1 day = 24 hours

1 hour = 60 minutes

1 minute = 60 seconds

=> 1 Year = 365.25 x 24 x 60 x 60 Seconds

But 1 billion seconds = ?

1 Year = 365.25 x 24 x 60 x 60 Seconds

    ?     =  1000000000 Seconds

? = 1000000000365.25 x 24 x 60 x 60 years = 31. 68 years.

River Dolphin is the National Aquatic Animal of India.

Longest and shortest phases Of cell cycle:

Shortest Phase - M phase or Mitotic phase.

Longest phase - G1 phase of the Interphase

Longest and shortest phases During Mitosis:

Longest Phase - Prophase

Shortest Phase - Anaphase

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

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