You plan to fly a model airplane of mass 0.390 kg that is attached to a horizontal string. The plane will travel in a horizontal circle of radius 5.90 m. (Assume the weight of the plane is balanced by the upward "lift" force of the air on the wings of the plane.) The plane makes 1.30 revolutions every 3.20 s.
a.) Find the speed at which you must fly the plane.
b.) Find the force exerted on your hand as you hold the string (assume the string is massless).