Answer:
, the minus meaning west.
Explanation:
We know that linear momentum must be conserved, so it will be the same before (
) and after (
) the explosion. We will take the east direction as positive.
Before the explosion we have
.
After the explosion we have pieces 1 and 2, so
.
These equations must be vectorial but since we look at the instants before and after the explosions and the bomb fragments in only 2 pieces the problem can be simplified in one dimension with direction east-west.
Since we know momentum must be conserved we have:

Which means (since we want
and
):

So for our values we have:

There is no change in ocean water temperature when it is from the ocean surface to a depth of 1 km.
Potential Energy = mgh,
where m = mass in kg, g ≈ 10 m/s², h = height above ground = 8 m
PE = mgh
= 70*10*8 = 5600 J