For this case we have that by definition, the momentum is given by:

Where,
- <em>m: mass
</em>
- <em>v: speed
</em>
Therefore, replacing values we have:

From here, we clear the value of the speed:

Answer:
The magnitude of velocity is:

the answer should be:
When the buoyant force is equal to the force of gravity
Radiation is the transfer of heat energy through space by electromagnetic radiation. Most of the electromagnetic radiation that comes to the earth from the sun is in the form of visible light. Light is made of waves of different frequencies.