ch 4 review 2015 Modified True/False Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true. 1. Speed is a variable that tells you how fast something is going and in what direction. _ 2. A steeper line on position vs. time graph means a slower speed. _ 3. When there is acceleration, a position vs. time graph is a curve. _ 4. Displacement includes both distance and direction. _ 5. Motion occurs when there is a change in speed. _ 6. If you were trying to get out of the way of a storm, you would need to know the speed at which it was moving. _ 7. Acceleration occurs when velocity changes. _ 8. If you roll a ball up a hill, it undergoes positive acceleration. _ 9. When you push on a sled and it begins to go downhill, you cause negative acceleration. _ Completion Complete each statement. Select the correct term to complete each sentence. Terms may be used more than once. constant speed positive average acceleration velocity frames of reference curved displacement instantaneous distance 10 vectors acclerate direction negative resultant vector initial final 10. The total distance traveled divided by the total time of a trip is called speed. 11. Speed that stays the same is called speed. 12. The speed you have at a specific point in your journey is best called speed. 13. The rate of change in the velocity of an object is called. 14. is a measure of how far an object has moved.
15. The speed and direction with which an object moves is its. 16. The distance an object travels per unit of time is. 17. The slope of the distance-time graph gives the. 18. Acceleration occurs when an object changes its or or both. 19. An object changing its speed from 10 m/s to 3 m/s is undergoing acceleration. 20. As a car slows down approaching a red traffic light its is negative. 21. When calculating acceleration, to find the change in velocity, you subtract the velocity from the velocity. 22. The motion of an object looks different to observers in different. 23. The direction and length of a straight line from the starting point to the ending point of an object s motion is. 24. Displacement and velocity are examples of because they have both magnitude and direction. 25. The sum of two or more vectors is called the _. 26. A car s speedometer measures _. 27. The difference between speed and velocity is that velocity indicates the of motion and speed does not. 28. A distance-time graph indicates an object moves 20 km in 2 h. The average speed of the object is km/h. 29. A moving object does not if its velocity remains constant. 30. A car that increases its speed from 20 km/h to 100 km/h undergoes acceleration. 31. A constant slope on a distance-time graph indicates speed. 32. Because its is always changing, an object moving in a circular path experiences a constant change in velocity. 33. Accelerated motion is represented by a(an) line on a distance-time graph. Matching Choose the type of acceleration from the list below that would BEST describe the motion of the objects described. Types of acceleration may be used once, more than once, or not at all.
a. positive acceleration b. negative acceleration c. no acceleration 34. A car traveling straight on a highway at 60 mph using cruise control 35. A motorcycle slowing down 36. A baseball dropped from the roof of a building 37. A girl on a skateboard going around a corner at a speed of 3 m/s 38. A truck parked at a rest area Short Answer 39. A truck travels to and from a stone quarry that is located 2.5 km to the east. What is its distance? What is its displacement? 40. A car is driving down a road. Is it possible for its position to be changing and its acceleration to be zero? Is it possible for its velocity to be changing and its acceleration to be zero? 41. A car has an acceleration of 5 m/s 2. Describe the car s motion. Problem 42. A cross-country runner runs 10 km in 40 minutes. What is his average speed? 43. A high speed train travels with an average speed of 227 km/h. The train travels for 2 h. How far does the train travel? 44. Find the acceleration of a car that goes from 32 m/s to 96 m/s in 8.0 s.
ch 4 review Answer Section MODIFIED TRUE/FALSE 1. ANS: F, velocity 2. ANS: F faster greater PTS: 1 DIF: basic REF: section 4.2 3. ANS: T PTS: 1 DIF: basic REF: section 4.3 4. ANS: T PTS: 1 DIF: B OBJ: 1/1 STA: PS.B.8.1 PS.B.8.2 5. ANS: F, position PTS: 1 DIF: B OBJ: 1/1 STA: PS.B.8.1 PS.B.8.2 6. ANS: F, velocity PTS: 1 DIF: B OBJ: 2/1 STA: PS.B.8.1 PS.B.8.2 7. ANS: T PTS: 1 DIF: B OBJ: 4/2 STA: PS.B.8.1 PS.B.8.2 8. ANS: F, negative PTS: 1 DIF: B OBJ: 5/2 STA: PS.B.8.1 PS.B.8.2 PS.B.8.3 9. ANS: F, positive PTS: 1 DIF: B OBJ: 5/2 STA: PS.B.8.1 PS.B.8.2 PS.B.8.3 COMPLETION 10. ANS: average 11. ANS: constant 12. ANS: instantaneous 13. ANS: acceleration PTS: 1 DIF: basic REF: section 4.3 14. ANS: Distance
PTS: 1 DIF: B OBJ: 1/1 STA: PS.B.8.1 PS.B.8.2 15. ANS: velocity PTS: 1 DIF: B OBJ: 2/1 STA: PS.B.8.2 PS.B.8.3 16. ANS: speed PTS: 1 DIF: B OBJ: 2/1 STA: PS.B.8.2 PS.B.8.3 17. ANS: speed PTS: 1 DIF: B OBJ: 3/1 STA: PS.B.8.2 PS.B.8.3 SI.B.7.7 SI.B.8.3 18. ANS: speed, direction PTS: 1 DIF: B OBJ: 4/2 STA: PS.B.8.1 PS.B.8.2 PS.B.8.3 19. ANS: negative PTS: 1 DIF: B OBJ: 6/2 STA: PS.B.8.1 PS.B.8.2 PS.B.8.3 20. ANS: acceleration PTS: 1 DIF: B OBJ: 5/2 STA: PS.B.8.1 PS.B.8.2 PS.B.8.3 21. ANS: initial, final PTS: 1 DIF: B OBJ: 6/2 STA: PS.B.8.2 PS.B.8.3 SI.B.8.4 22. ANS: frames of reference PTS: 1 DIF: L1 OBJ: 11.1.1 23. ANS: displacement PTS: 1 DIF: L1 OBJ: 11.1.3 24. ANS: vectors PTS: 1 DIF: L2 OBJ: 11.1.3 25. ANS: resultant vector PTS: 1 DIF: L1 OBJ: 11.1.4 26. ANS: instantaneous speed PTS: 1 DIF: L1 OBJ: 11.2.2 27. ANS: direction PTS: 1 DIF: L1 OBJ: 11.2.3 28. ANS: 10 PTS: 1 DIF: L2 OBJ: 11.2.4 29. ANS: accelerate PTS: 1 DIF: L1 OBJ: 11.3.1 30. ANS: positive
PTS: 1 DIF: L2 OBJ: 11.3.5 31. ANS: constant PTS: 1 DIF: L2 OBJ: 11.2.3 32. ANS: direction PTS: 1 DIF: L1 OBJ: 11.2.5 33. ANS: curved PTS: 1 DIF: L2 OBJ: 11.3.4 MATCHING 34. ANS: C PTS: 1 DIF: intermediate REF: section 4.3 35. ANS: B PTS: 1 DIF: intermediate REF: section 4.3 36. ANS: A PTS: 1 DIF: intermediate REF: section 4.3 37. ANS: A PTS: 1 DIF: intermediate REF: section 4.3 38. ANS: C PTS: 1 DIF: intermediate REF: section 4.3 SHORT ANSWER 39. ANS: 5 km, 0 km PTS: 1 DIF: B OBJ: 1/1 STA: PS.B.8.1 SI.B.8.4 40. ANS: Yes, it could have constant speed. No, a change in velocity is always an acceleration. PTS: 1 DIF: A OBJ: 4/2 STA: PS.B.8.1 PS.B.8.2 PS.B.8.3 41. ANS: The car is slowing down at the rate of 5 m/s every second. PTS: 1 DIF: A OBJ: 5/2 STA: PS.B.8.1 PS.B.8.2 PS.B.8.3 PROBLEM 42. ANS: s = d/t = 10 km/40 min = 0.25 km/min PTS: 1 DIF: A OBJ: 2/1 STA: PS.B.8.1 PS.B.8.2 PS.B.8.3 SI.B.8.4 43. ANS: d = s y = 227 km/h (2.00 h) = 454 km PTS: 1 DIF: A OBJ: 2/1 STA: PS.B.8.1 PS.B.8.2 PS.B.8.3 SI.B.8.4 44. ANS:
v f v i /t = (96 m/s 32 m/s)/ 8.0 s = 8.0 m/s 2 PTS: 1 DIF: A OBJ: 6/2 STA: PS.B.8.1 PS.B.8.2 PS.B.8.3 SI.B.8.4