Answer:
7066kg/m³
Explanation:
The forces in these cases (air and water) are: Fa =mg =ρbVg Fw =(ρb −ρw)Vg where ρw = 1000 kg/m3 is density of water and ρb is density of the block and V is its density. We can find it from this two equations:
Fa /Fw = ρb / (ρb −ρw) ρb = ρw (Fa /Fa −Fw) =1000·(1* 21.2 /21.2 − 18.2)
= 7066kg/m³
Explanation:
Answer:
I don't know this answer because I am not American
An object is in motion if its distance from another object is changing. An object is in motion if it changes position relative to a reference point. An reference point is a place or object used for comparison to determine if something is moving.
Answer:
Vapors
Explanation:
We take into account that all the energy from the lightning has been transformed into steam.

We calculate the amount of energy required by water to convert into steam.



From the lightning we received
of energy, out of which
has been used to convert the water into steam.
Energy left = 
We use this energy to convert steam into vapors.


With this temperature, we can easily interpret that the vapors will be dissociated in hydrogen and oxygen particles.
The concept needed to solve this problem is average power dissipated by a wave on a string. This expression ca be defined as

Here,
= Linear mass density of the string
Angular frequency of the wave on the string
A = Amplitude of the wave
v = Speed of the wave
At the same time each of this terms have its own definition, i.e,
Here T is the Period
For the linear mass density we have that

And the angular frequency can be written as

Replacing this terms and the first equation we have that



PART A ) Replacing our values here we have that


PART B) The new amplitude A' that is half ot the wavelength of the wave is


Replacing at the equation of power we have that

