Final answer:
The question covers concepts from high school physics, including forces in equilibrium with tension components, magnetic torque on a current-carrying loop, and the Doppler effect involving observed frequency changes.
Step-by-step explanation:
The question appears to be related to the subject of physics, specifically involving the concepts of forces and torque in relation to trigonometric functions. The provided equations are similar to those in equilibrium problems where tension forces are broken down into components using sine functions. In the appropriate physical context, if we know the weight w and we have an expression to substitute into the equation for T2 in terms of T1, we can solve for the single unknown, T1.
Additionally, the mention of a torque T involving a loop with N turns is related to magnetic effects on a current-carrying loop in a magnetic field, which is again a topic in high school physics. Here, the torque is dependent on the magnetic field strength B, the current I, and the area A of the loop, which is calculated using its width w and length l.
The final part related to a frequency observed by a stationary person as a train approaches pertains to the Doppler effect, another concept in physics that explores how the frequency of waves changes due to the relative motion between the source and an observer.