The angle subtended at an observer by a city transit bus (length 9 m) at a distance of 1000 m is close to
A) 1000/9, or 111.1 arcseconds.
B) ½ of a degree.
C) 9000 arcminutes.
D) 9/1000, or 0.009 arcseconds.

Question

Quizplus · Accepted Answer

The angle can be approximated using the small angle formula, which in radians is angle = length / distance. Converting 9/1000 radians to degrees (since 1 radian = 57.2958 degrees), we get approximately 0.515 degrees, which is close to ½ of a degree.

The Angle Subtended at an Observer by a City Transit