Abeam of light in air is incident on the surface of a rectangular block of clear plastic (n = 1.44 ). if the velocity of the beam before it enters the plastic is 3.00 · 108 m/s, what is its velocity inside the block?

using this formula

n = V1/V2 ( you make V2 subject )

it becomes:

V2 = V1/n ( put in your values and cal.)

Explanation:

refractive index

= velocity in first medium / velocity in the second medium

NB : there's other ways to find refractive index, depending on the values you were given

i would think form in reponse to tensional forces

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.