(a) 
The frequency of a wave is given by:
where
v is the wave's speed
is the wavelength
For the red laser light in this problem, we have
(speed of light)
Substituting,
(b) 427.6 nm
The wavelength of the wave in the glass is given by
where
is the original wavelength of the wave in air
n = 1.48 is the refractive index of glass
Substituting into the formula,
(c) 
The speed of the wave in the glass is given by
where
is the original speed of the wave in air
n = 1.48 is the refractive index of glass
Substituting into the formula,
Answer:
Light refracts when its speed changes as it enters a new medium.
Explanation:
Bending of light wave while it entering a medium with different speed is called refraction of light. Light passing from a faster medium to the slower medium bends the light rays toward the normal to boundary between two media. The amount of the bending of light depends on refractive index of the two media which is described by the Snell's Law. The angle of incidence is not equal to angle of refraction. Rainbow is caused but this refraction phenomena. Also Refraction is used in magnifying glasses, prism and lenses
<h2>
Answer</h2>
The physical state of the elements depends upon the <u>attraction forces </u>and their <u>kinetic energy</u>.
<h2>
Explanation</h2>
The elements or substances are fixed with each other with the help of different chemical forces including ionic bonding, covalent bonding, H- bonding etc. The strength of these forces is also one of the factors that affect their physical natures. For example, covalent or ionic bonds are the strongest bonds than all other bonds and metals that contain these forces are mostly in solid form. The kinetic motion of electrons in the element also affects the physical state of the element and potential of bonding.
