1. Motion 2: Problem Set 1

2. DIRECTIONS Answer the questions and solve the problems on a separate sheet of paper. Be sure to show all work on the problems which means show the equation used, the filled in equation and give the final answer with the appropriate unit(s).

3. EQUATIONS AND CONVERSIONS Conversion Factors: Constants: 1 kilogram = 2.2 pounds g earth = 9.8 m/sec 2 1000 grams = 1 kilogram 1 pound = 16 ounces 1 centimeter = 0.39379 inches 100 centimeters = 1 meter 1000 meters = 1 kilometer 1 mile = 5280 feet 1 kilometer = 0.62 miles a = v f - v i F = m∙a p = m∙v w = m∙ g t a =  v s = d v = d t t t

4. 1. If the shark is circling at a rate of 2.5 m/sec, is the shark accelerating? Explain.

5. 1. The shark is accelerating even though it is traveling at the same speed because the shark is constantly changing direction.

6. 2. How fast does the flamingo fly if it covers 4.3 meters in 1.7 seconds?

7. 2. s = d = 4.3 m = 2.5 m/sec t 1.7 sec

8. 3. How long will it take the lobster to get to the island if it accelerates from 0.4 m/sec to 0.7 m/sec at 0.3 m/sec/sec?

9. 3. a = v f - v i t 0.3 m/sec/sec = 0.7 m/sec – 0.4 m/sec t t = 1 sec

10. 4. Tourists see the lobster and try to catch it. If the lobster has a mass of 0.8 kg and runs at a pace of 0.6 m/sec, what is the lobster’s momentum?

11. 4. p = m ∙ v p = (0.8 kg)(0.6 m/sec) p = 0.48 kg∙m/sec

12. 5. Two groups of twins have a tug of war contest. Neither team can make the other team move. Is this a balanced or unbalanced force?

13. 5. These are balanced forces since there is no motion.

14. 6. How fast does the hamster run if he covers 4.3 m in 8.6 seconds?

15. 6. s = d = 4.3 m = 0.5 m/sec t 8.6 sec

16. 7. This is an angry bear. He thinks you ate his blueberries. If he is 15 meters away from you and walking at 2.3 m/sec, how long will it take him to reach you?

17. 7. v = d t 2.3 m/sec = 15 m t t = 6.5 sec toward you

18. 8. What is the giraffe’s final velocity if it starts with a velocity of 2.4 m/sec and accelerates at 0.4 m/sec/sec in 45 seconds?

19. 8. a = v f - v i t 0.4 m/sec/sec = v f – 2.4 m/sec 45 sec v f = 20.4 m/sec

20. 9. What is the net force acting on a 1.5 kg soccer ball that has an acceleration of 3.5 m/sec 2 ?

21. 9. F = m∙a F = (1.5 kg)(3.5 m/sec 2 ) F = 5.25 kg∙m/sec 2 = 5.25 N

22. 10. What is the momentum of a 18,342 kg RV that is traveling eastward at a velocity of 13.7 m/sec?

23. 10. p = m∙v p = (18,342 kg)(13.7 m/sec) p = 251,285.4 kg∙ m/sec

24. 11. a. What is the mass of a bowling ball that moves 8.7 m/sec down the alley with a momentum of 55 kg  m/sec?

25. 11. p = m∙v 55 kg  m/sec = (m)(8.7 m/sec) m = 6.3 kg

26. 11. b. What is the weight of that bowling ball?

27. 11. w = m∙g w = (6.3 kg)(9.8 m/sec 2 ) w = 61.7 kg∙m/sec 2 = 61.7 N

28. 12. How much does a 16.5 kg dog weigh on Earth?

29. 12. w = m∙g w = (16.5 kg)(9.8 m/sec 2 ) w = 161.7 kg∙m/sec 2 = 161.7 N

30. 13. Calculate the momentum of a 12.6 pound toddler crawling down the hall at 0.78 m/sec.

31. 13. 12.6 lb | 1 kg = 5.7 kg |2.2 lb p = m∙v p = (5.7 kg)(0.78 m/sec) p = 4.4 kg  m/sec