Answer:
The speed of water must be expelled at 6.06 m/s
Explanation:
Neglecting any drag effects of the surrounding water we can assume the linear momentum in this case is conserves, that is, the total initial momentum of the octopus and the water kept in it cavity should be equal to the total final linear momentum. That's known as conservation of momentum, mathematically expressed as:

with Pi the total initial momentum and Pf the final total momentum. The total momentum is the sum of the momentums of the individual objects, in our case the octopus and the mass of water that will be expelled:

with Po the momentum of the octopus and Pw the momentum of expelled water. Linear momentum is defined as mass times velocity:

Note that initially the octopus has the water in its cavity and both are at rest before it sees the predator so
:

We should find the final velocity of water if the final velocity of the octopus is 2.70 m/s, solving for
:


The minus sign indicates the velocity of the water is opposite the velocity of the octopus.
A-11 polar easterlies
b-8 winds blowing between the equator and 30° N and south
c-10
d-9
Explanation:
(a) Since, it is given that the blocks are identical so distribution of charge will be uniform on both the blocks.
Hence, final charge on block A will be calculated as follows.
Charge on block A =
= 4.35 nC
Therefore, final charge on the block A is 4.35 nC.
(b) As it is given that the positive charge is coming on block A
. This means that movement of electrons will be from A to B.
Thus, we can conclude that while the blocks were in contact with each other then electrons will flow from A to B.
Answer:
They diverge on refraction
Explanation:
When parallel light rays strike a concave lens, they will diverge that is they spread out .
Concave lens is also known as diverging lens, which means that when parallel rays of light strike on it, the lens spreads out the light rays ( that is it diverges the rays of light) that are refracted through it.
At the middle of concave lens is thinner.
When light is passes through the lens they diverge it or spread out.
The concave lens causes light rays to bend away or diverge from its axis since the concave lens is a diverging lens.