Answer: wave
Explanation:
These are the basic definitions and characteristic of the terms given, which show tha the only rigth answer is the second option: wave.
1) Force is an interaction. There are four natural forces: electrostatic, gravity, strong nuclear force and weak nuclear force.
2) Wave: is a sequence of pulses or vibrations that cause the continuous transportation of energy (propagation). There is not transport of mass, only energy.
Some examples of waves are sound waves, electromagnetic waves (light, radio waves, micro waves, infrarred waves, ultraviolet waves).
3) Vacuum: is the absence of matter; empty space. Only electromagnetic waves can travel through vacuum; other waves need a medium to travel.
4) Medium: any matter is a medium: a solid, the air, a liquid, all of them are media through which waves can transport its energy, depending of the wavelength.
A). Her distance traveled was (700m + 500m) = <em>1,200 meters</em>
B). Her displacement was (700m north + 500m south) = <em>200 meters north</em>
C). Her average speed = (distance covered) / (time to cover the distance)
Speed = (1,200 meters) / (15 seconds)
<em>Speed = 80 meters/second</em>
(Layne is an incredible walker ! That's about 179 miles per hour.)
(She walks 700m in 10 seconds. Usain Bolt runs only 100m in 10 seconds.)
D). Her averge velocity = (displacement) / (time)
Velocity = (200 meters north) / (15 seconds)
<em>Velocity = (13 and 1/3) m/s north</em>
(This is only about 33% faster than Usain Bolt, if he went straight instead of doubling back, and if he could keep it up for 200 meters instead of only 100 meters.)
178 centimeters is exactly, precisely, the same length as ...
-- 0.00178 kilometer
-- 1.78 meters
-- 1,780 millimeters
-- 1,780,000 micrometers
-- 1,780,000,000 nanometers
1. Single dental x-rays: 
The energy of the photon is
Using the conversion factor
we can convert it into Joules:
The relationship between photon energy and wavelength is
where
is the Planck constant
is the speed of light
E is the energy
Substituting into the formula, we find
2. Microtomography: 
The energy of these photons is 2.5 times greater, so
And by applying the same formula used at point 1, we find the corresponding wavelength:
