1. A bird goes into a flight pattern which involves a semi-circular path at the bottom. The 20 m semicircle has a radius of 20 m. The bird's mass is 0.50 kg. A The bird has a constant speed of 10 m s '1. B (a) What is the magnitude of the net force on the bird at point A? (b) What is the magnitude of the net force on the bird at point B? (c) What is the magnitude of the upward force exerted on the bird by the air at point B