Answer:
B) waves speed up
C) waves bend away from the normal
Explanation:
The index of refraction of a material is the ratio between the speed of light in a vacuum and the speed of light in that medium:

where
c is the speed of light in a vacuum
v is the speed of light in the medium
We can re-arrange this equation as:

So from this we already see that if the index of refraction is lower, the speed of light in the medium will be higher, so one correct option is
B) waves speed up
Moreover, when light enters a medium bends according to Snell's Law:

where
are the index of refraction of the 1st and 2nd medium
are the angles made by the incident ray and refracted ray with the normal to the interface
We can rewrite the equation as

So we see that if the index of refraction of the second medium is lower (
), then the ratio
is larger than 1, so the angle of refraction is larger than the angle of incidence:

This means that the wave will bend away from the normal. So the other correct option is
C) waves bend away from the normal
Answer:
x=0.46m, speed=7.9m/s
Explanation:
Using the concept of conservation of energy:
1. kinetic energy of mass m and velocity v: 
2. gravitational potential energy of mass m, grav. acc. g and height h: 
3. potential energy in a spring with spring constant k and displacement from equilibrium x: 
Calculating x:


Calculating the speed:



Solving for
:

"Average velocity" is the vector among the choices given in the question that describes <span>how fast an object moves over a long time interval. The correct option among all the options that are given in the question is the last option or the fourth option. I hope the answer has helped you.</span>
<span>So we want to know when do we have enough information about the atom that we can say that it is electrically neutral. So the information we need to know is the number of protons, whic are positively charged particles and the number of electrons which are negatively charged particles. Number of protons has to be equal to number of electrons for the atom to have neutral charge. Neutrons are electrically neutral so their number doesn't change the charge of the atom. So the correct answer is B. </span>
The correct answer is this one: "length of address." The element that is not part of Aristotle's rhetorical triangle is the length of the address. The rhetorical triangle of Aristotle are the logos, pathos, and ethos. Logos is the logic, Pathos is the audience emotion, Ethos is the speaker's credibility.