A) 1.55
The speed of light in a medium is given by:

where
is the speed of light in a vacuum
n is the refractive index of the material
In this problem, the speed of light in quartz is

So we can re-arrange the previous formula to find n, the index of refraction of quartz:

B) 550.3 nm
The relationship between the wavelength of the light in air and in quartz is

where
is the wavelenght in quartz
is the wavelength in air
n is the refractive index
For the light in this problem, we have

Therefore, we can re-arrange the equation to find
, the wavelength in air:

Can neither be created or destroyed.
Tides are influenced by the force of gravity exerted by the earth, moon and the sun. The sun has a larger mass than the moon and as such has a greater gravitational pull on the earth. the moon however has greater influence over the tides because they are caused by the difference in gravity fields. This means that the moon is the dominant influence due to the fact that the fractional difference in its force across the earth is greater than that seen from the sun.
Answer: higher and lower
Explanation:
charge in an electric field will experience a force in the direction of decreasing potential energy. Since the electric potential energy of a negative charge is equal to the charge times the electric potential the direction of decreasing electric potential energy is the direction of increasing electric potential.
Now the vertical velocity of the ball thrown at an angle 10° is given as
Voy(initial vertical velocity)= 30m/s x sin 10
Voy(initial vertical velocity)= 5.2m/s
Now the ball is decelerating with an acceleration due to gravity equivalent to 9.8m/s^2.
Let Vy be the final velocity and that is equal to zero in this case.
Now
Vy= Voy- tx9.8
Where t is the time at which the vertical velocity becomes 0.
Substituting the values we get
0= 5.2-tx9.8
9.8t=5.2
t=0.53 secs