Answer:
The answer is <em>e.2</em>
Explanation:
We should make use of Snell's refractive law. The arriving wave has a certain velocity at T in a medium, then instantly it reaches a medium (same composition) at T' where velocity would either decrease or increase.
When the incidence angle is 30 °, and we want to make the refraction angle 90 ° such that no sound passes through the barrier (this would be named total internal refraction), so we want the second medium to be "faster" than in the first.
<em>The steps are in the image attached:</em>
B. In step 3
They incorrectly solved for x. It should have been x=-3 and x=5
<span>Suppose that an electric charge is produced on one part of a body. If the charge spreads through the entire body, the body is most likely made of metal. </span>
<span>In an internal combustion engine, heat flow into a gas causes it to expand.
The application of direct force to specific parts of the engine will produce </span>expansion of the high-temperature<span> and high-</span>pressure<span> gases. Which will transform the chemical energy from the fuel (such as gasoline or oi) into mechanical energy.</span>