The dolphin would send an underwater message because the water is denser than air and therefore the sound would be louder and would travel faster. The denser the object the faster the sound travels.
Answer:
the maximum mass that can hang without sinking is 2.93 kg
Explanation:
Given: details:
sphere diameter d = 20 cm
so, radius r = 10 cm = 0.10 m
density of the Styrofoam sphere D = 300 kg/m3
sphere volume 

=4.18*10^{-3} m^3
we know that

mass M = Density * Volume
= (300)(4.18*10^{-3} m3)
=1.25 kg
mass of the water displace = volume *density of water
= 4.18*10^{-3} m3 * 1000
= 4.18 kg
The difference between the mass of water and mass of styrofoam is the amount of mass that the sphere can support
=4.18 kg -1.25 kg
= 2.93 kg
The process of changing from one phase of matter to another is a physical matter.
The chemical reaction causes electricity to flow through the terminals to the load attached. Some of the acid in the battery remains on the plates as it flows through. When the battery is recharged the acid is returned to the liquid solution to provide more power later.
Copper, because it has the lowest specific electrical resistance.
specific electrical resistance aka volume resistivity is a fundamental property of a material that quantifies how strongly that material opposes the flow of electric current. A low resistivity indicates a material that readily allows the flow of electric current.