Answer:
I think you are looking for the velocity, so the answer is 38.5 m/s
Explanation:
Velocity is giving by displacement/time. North will be positive and South will be negative, George travels 750 meters then travels -250 meters his displacement is then 750 - 250 or 500 meters. Divide that by 13 seconds to get 38.5 m/s.
False does not last that long
Answer:
a) 
b) infrared region
Explanation:
Photon energy is the "energy carried by a single photon. This amount of energy is directly proportional to the photon's electromagnetic frequency and is inversely proportional to the wavelength. If we have higher the photon's frequency then we have higher its energy. Equivalently, with longer the photon's wavelength, we have lower energy".
Part a
Is provide that the smallest amount of energy that is needed to dissociate a molecule of a material on this case 0.42eV. We know that the energy of the photon is equal to:

Where h is the Planck's Constant. By the other hand the know that
and if we solve for f we have:

If we replace the last equation into the E formula we got:

And if we solve for
we got:

Using the value of the constant
we have this:


Part b
If we see the figure attached, with the red arrow, the value for the wavelenght obtained from part a) is on the infrared region, since is in the order of 
Answer:

Explanation:
We know that impedance of a RLC circuit is given by 
So
here R is resistance
is inductive reactance and
is capacitive reactance
To minimize the impedance
should be zero we know that 
So 


We know that 
So 

Where f is resonance frequency
Answer: Explained below
Explanation: The calculations are not very accurate. The distance would be underestimated because double crossovers are not observed.