For the first one, the correct answer would be "<span>Substance changes its form but not its molecular composition.". During a physical change (let's say cutting paper), the substance has its shape changed, but it is still itself (paper).
</span><span>The second one is a bit trickier: </span>
Kinetic energy of a molecule is directly influenced by temperature. If there is a higher temperature it will have a higher kinetic energy which means the molecule moves at a higher velocity. This will increase the chance of particles bouncing off of each other during the chemical reaction. That explains why the rate of reaction will be higher at a higher temperature, rather than higher at a cool temperature. The correct answer would be lower at 39F.
AC reverses the current in periods, and the current flows in 2 directions.
DC only flows in one direction and is constant.
AC is typically used to transfer power over long distances from a generator to your home, stepping it up after it's generated to send it over the distance, then stepping it back down so that it is usable in your home.
DC is used typically inside of devices, as it sends a certain amount of electricity through the wires.
Nicolas Tesla, was ripped off by Edison to replace his DC stations with AC instead. ^^
Answer: lambda 
, nu 
, and 100E
Explanation:
The energy 
of a photon is given by:
(1)
Where:
is the Planck constant
is the frequency
On the other hand, we have an expression that relates the frequency of the photn with its wavelength :
(2) where 
is the speed of light
Substituting (2) in (1):
(3) This is the energy for a single photon
For 100 photons, the energy is:
(3)
Where the wavelength and the frequency of the light remains constant.
Therefore, the answer is:
, , and 100E
It would ultimately cost the government more considering it doesnt break down.
Ball C has the greatest momentum and ball B has the least amount of momentum.
