An airplane is in supersonic flight at an altitude h. At what smallest distance a (along the horizontal) from the observer on the ground is there a point from which the sound emitted by the airplane motors travels to the observer faster than from point A that is directly above the observer –

(a) a<2(v_p/v_s )/((v_p/v_s )^2-1) h
(b) a<((v_p/v_s ))/((v_p/v_s )^2-1) h
(c) not possible for any real value of a
(d) a>2(v_p/v_s )/((v_p/v_s )^2-1) h
where vp = velocity of airplane, vs = velocity of sound

Kevin Nash , 12 Years ago

Grade upto college level