Well as the fish swims he pushes the water behind him which in return push him forward
Let's call

the mass of the glider and

the total mass of the seven washers hanging from the string.
The net force on the system is given by the weight of the hanging washers:

For Newton's second law, this net force is equal to the product between the total mass of the system (which is

) and the acceleration a:

So, if we equalize the two equations, we get

and from this we can find the acceleration:
To locate a specific target or to determine how close submarines are to the seafloor, they use active and passive sound navigation and ranging (or a SONAR, in simple terms.) It emits pulses of sound waves that travel through the water, reflect off the target and relayed back to the ship. By determining how fast the sound wave travels back, the computers on the sub calculate how far they are from the target.
Hope this helps.
For the answer to the question above asking to d<span>etermine the density of the proton.
</span>Density is mass over volume.
The volume of a sphere is 4πr³/3. r is half the diameter.
So the density would be 2.3×10¹⁷ kg/m³.
I hope my answer helped you. Feel free to ask more questions. Have a nice day!
The answer to this question is D or the last one