A Jet Aircraft, in Level Flight at Constant Speed, Is

Multiple Choice

A jet aircraft, in level flight at constant speed, is observed directly over head. A sonic boom is heard 13.0 s later, at which time the line of sight to the aircraft forms a 51° angle with respect to the horizontal. The speed of sound is 325 m/s. The altitude of the aircraft is closest to

A) 6700 m.
B) 5400 m.
C) 8300 m.
D) 2700 m.
E) 13,000 m.