What is the net force on the table due to Bettys and Sallys pushes?
15 N B) 5 N C) 50 N D) 2 N D) It depends on the direction they are pushing. • Let us look at a bird, flapping its wings, flying. What are the forces acting on it ? A) Gravity, air resistance. B) Just air resistance; the gravity has been overcome – the bird is flying. C) Gravity, air resistance, reaction from air (pushing on its wings); this is why it can fly D) Gravity, no air resistance; this is how it flies, slipping through air. E) No forces; upward pressure of air exactly cancels gravity (this is why it can fly) A) B) C) D) –> • Because of gravity, the Earth exerts a force on a falling apple. How does this force (on the apple) compare to the force the apple exerts on the Earth. A) The two forces are exactly equal but opposite in direction. B) The Earth exerts a large force on the apple, the apple a tiny force on the Earth. C) The apple clearly exerts no force on the Earth. D) The force of the Earth on the apple depends on the air resistance on the apple. • A book is dropped and fa
