Chapters 3 & 4, example #1 Which is greater, an acceleration for an object A of mass 80 kg from a speed of 10 m/s to 20 m/s in 5 sec. or a second object B of mass 60 kg from 20 m/s to 25 m/s in 2 sec.? Which one of these two objects is subject to a greater force? Ans: The object B has a greater acceleration, but, the object A is subject to a greater force. Chapters 3, 4, and 5, example #1 In an attempt to jump from the floor, you apply a force of 3600 N to the floor, how large is the force that accelerates your body upward? What is your upward acceleration assuming that your mass is 60 kg? Let’s further assume that it takes 0.05 sec. for your body to leave the floor, what is your initial vertical speed upward? What is your hang time? Ans: The force that accelerates your body upward is 3600 N. Your upward acceleration is 60 m/s2. Your initial speed leaving the floor is 3 m/s and your hang time is 0.6 sec. Chapter 4, example #1 What would be the acceleration of a free falling object of mass m with an air resistance equal to 70% of its weight? Ans: 3 m/sec2