An Airplane Flies in a Horizontal Circle of Radius 500

Multiple Choice

An airplane flies in a horizontal circle of radius 500 m at a speed of 150 m/s. If the radius were changed to 1000 m, but the speed remained the same, by what factor would its centripetal acceleration change?

A) 0.25
B) 0.50
C) 1.00
D) 2.00
E) 4.00