University Physics Wolfgang Bauer Gary Westfall Chapter 6
University Physics Wolfgang Bauer Gary Westfall Chapter 6 Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.
6. 1 In-Class Exercise A person pushes a box with mass 10. 0 kg a distance of 5. 00 m across a floor. The coefficient of kinetic friction between the box and the floor is 0. 250. The person then picks up the box, raising it to a height of 1. 00 m, carries the box back to the starting point, and puts it back down on the floor. How much work has the person done on the box? a) 0 J b) 12. 5 J c) 98. 1 J d) 123 J e) 25. 0 J f) 246 J
6. 2 In-Class Exercise The potential energy, U (x), is shown as a function of position, x, in the figure. In which region is the magnitude of the force the highest? a) b) c) d)
6. 3 In-Class Exercise What is the maximum acceleration that the human cannonball of Solved Problem 6. 2 experiences? a) 1. 00 g b) 2. 14 g c) 3. 25 g d) 4. 48 g e) 7. 30 g
6. 4 In-Class Exercise A ball of mass m is thrown vertically into the air with an initial speed v. Which of the following equations correctly describes the maximum height, h, of the ball? a) b) c) d) e)
6. 5 In-Class Exercise At the moment of maximum stretching of the bungee cord in Example 6. 2, what is the net acceleration that the jumper experiences (in terms of g = 9. 81 m/s 2) ? a) 0 g b) 1. 0 g, directed downward c) 1. 0 g, directed upward d) 2. 1 g, directed downward e) 2. 1 g, directed upward
6. 6 In-Class Exercise A curling stone of mass 19. 96 kg is given an initial velocity on the ice of 2. 46 m/s. The coefficient of kinetic friction between the stone and the ice is 0. 0109. How far does the stone slide before it stops? a) 18. 7 m b) 28. 3 m c) 34. 1 m d) 39. 2 m e) 44. 5 m
6. 7 In-Class Exercise Which of the four drawings represents a stable equilibrium point for the ball on its supporting surface?
Answer Key – Chapter 6 6. 1 6. 2 6. 3 6. 4 6. 5 6. 6 6. 7 a a d e e b b
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