Two vehicles, each moving with speed u on the same horizontal straight road, are approaching each other. Wind blows along the road with velocity w. One of these vehicles blows a whistle of frequency f₁. An observer in the other vehicle hears the frequency of the whistle to be f₂. The speed of sound in still air is V. The correct statement(s) is(are)

A horizontal stretched string, fixed at two ends, is vibrating in its fifth harmonic according to the equation

y(x, t) = (0.01 m) sin[(62.8 m^$$-$$1)x] cos[(628 s^$$-$$1)t]

Assuming $$\pi$$ = 3.14, the correct statement(s) is(are)

Under the influence of the Coulomb field of charge +Q, a charge $$-$$q is moving around it in an elliptical orbit. Find out the correct statement(s):