Part A: Identify the choice that best completes the statement or answers the question. Your choices are given below the text box. Make sure you include your strategy. 1. A tractor pulls a large tree stump across a field at a constant velocity with a horizontal force. If the force of the tractor on the tree stump doubles, then a. the velocity of the tree stump will double b. the acceleration of the tree stump will double c. the kinetic friction of the tree stump will double d. the tree stump will begin to accelerate 2. Which of the following is/are true about coefficients of kinetic friction between two substances? a. they are calculated by dividing the magnitude of the force of kinetic friction by the magnitude of the normal force b. they have different values depending on the substances c. they are usually less than the coefficients of static friction d. all of the above 3. The coefficient of static friction between a 1.2-kg book and a table is 0.32, and the coefficient of kinetic friction is 0.27. The minimum force required to start the book moving is a. 3.8 N b. 3.2 N b. 3.2 N c. 12 N d. 0.39 N d. 0.39 N 4. A 120-g block of wood rests on a lab bench. The coefficient of static friction between the wood and the bench is 0.27 and the coefficient of kinetic friction is 0.22. The force required to move the block across the bench at a constant velocity is a. 0.26 N b. 0.032 N c. 0.32 N d. 0.026 N 5. A large football player running east tackles a smaller football player running west. The smaller football player gets knocked backwards because a. the large player exerts a force on the small player first b.the large player exerts more force on the small player than the small player exerts on the large C. the small player exerts more force on the lar player than the large player exerts on the small d. none of the above Part B (Putting the Concepts to Work): Completion: Using your reading, answer the following questions. Give your answer as well as your strategy for determining your answer. As part of your answer, give the page number in the reference material or the website that you used to find the answer to the question. 6. A horizontal force of 110 N [forward] is required to get a 35 kg box to start moving across a floor. Calculate the coefficient of static friction (use an FBD if necessary). 7. A horizontal force of 61N [E] is required to get a 62 kg skater to start moving across the ice. Calculate the coefficient of static friction (use a FBD if necessary). 8. A horizontal force of 6.4 N [E] is required to move a 65-kg skater at a constant velocity across the ice. Calculate the coefficient of kinetic friction. 9. A horizontal force of 52N [W] is required to move a 19-kg suitcase at a constant velocity across the floor. Calculate the coefficient of kinetic friction. 10. A 35 kg boy slips and falls on the ice as he is skating forward. The coefficient of friction between the boy and the ice is 0.18. Find the acceleration of the boy