Name: Date Due: Motion. Physical Science Chapter 2

Transcription

1 Name: Date Due: Motion Physical Science Chapter 2

2 What is Motion? 1. Define the following terms: a. motion= a. frame of reference= b. distance= c. vector= d. displacement= 2. Why is it important to have a frame of reference when describing motion? 3. How can you tell if an airplane is moving across the sky? 4. Imagine that you are a passenger in a car. Circle the letter of the best frame of reference you could use to determine how fast the care is moving relative to the ground. a. the people sitting next to you in the backseat b. the driver of the car c. a van traveling in the lane next to your car d. a sign post on the side of the road 5. Think of a short route you commonly take, such as the route from your home to a friend s house or your school. Describe the direction(s) and distance(s) you travel over this route. 6. How are distance and displacement different? 2

3 7. Is the following sentence true of false? Five blocks south is an example of a displacement. 8. How do you add displacements? 9. You are going to calculate distance and displacement. Show all your work! a. A bug walks across a table. He starts going north for 3 cm, then changes direction and goes west for 8 cm. Finally, he turns southwest and travels for 9cm. Draw and calculate the distance. b. A motorist goes 10 kilometers east and stops. The she goes another 5 kilometers east. Draw and calculate the displacement vector. c. Margaret walks 52 meters in one direction. Then she remembers she needed talk to Mr. Palmer, and walks back 23 meters. Draw and calculate the displacement vector. 3

4 Speed 10. Define the following terms: a. speed= e. average speed= f. instantaneous speed= g. constant speed= 11. What are the units for speed? 12. What is the equation for average speed? 13. How are instantaneous speed and average speed different? 14. What shows speed on a distance-time graph? 15. What kind of graph is a distance time graph? 16. Does a car s speedometer show instantaneous speed or average speed? 17. Describe an experiment you could preform to determine average speed of a toy car rolling down an incline. 4

5 18. Directions: use the speed formula to solve the following problems. Show Work!! A. Sally decided to drive to her grandmother s house. She drove 117 miles in 2 hours, what was her average speed? B. Help Jimmy figure out how far he drove. He knew that his average speed was 75 mph and that he drove 6 hours. How far did he drive? C. If Jamie wants to arrive at her aunt s house on time for dinner, when will she need to leave her apartment if she only drives the speed limit (65 mph) and her aunt lives 30 miles away. D. Henry drove for one hour. During that time he looked down at the speedometer every 5 minutes to make sure he was driving the speed limit. If the speed limit is 65 mph, explain why Henry had driven only 50 miles during that time. E. Sondra drove 200 miles in 3 hours in the morning then got hungry and stopped at McDonalds for 30 minutes to eat a Big Mac. She finished her trip driving 240 miles in 4 hours. a) What was Sondra s speed in the morning? b) What was Sondra s speed after lunch? c) What was Sondra s average speed for the trip? 5

6 Velocity 19. Define the following terms: a. velocity= 20. How are speed and velocity different? 21. How do velocities add? 22. What are the three types of changes in velocity? 23. Does a car s speedometer show instantaneous speed, average speed, or velocity? 24. Circle the letter of each sentence that describes a change in velocity. a. A moving object gains speed. b. A moving object changes direction. c. A moving object moves in a straight line at a constant speed. d. A moving object slows down. 25. Is the following sentence true or false? If a car travels around a gentle curve on a highway at 60 km/h, the velocity does not change. 26. A vehicle travels 2345 m in 315 s toward the evening sun. What is its velocity? 27. Which of the following is not a possible unit for velocity? a. centimeters/month South b. millimeters/kilowatt West c. decimeters/kilosecond North d. kilometers/millisecond East 6

7 Name: Acceleration 28. Define the following terms: a. acceleration= h. average acceleration = i. instantaneous acceleration = 29. What are the three types of changes in velocity? 30. What are the units for acceleration? 31. Explain a situation in which you can accelerate even though your speed doesn t change. 32. How do you calculate acceleration? 33. As a roller coaster starts down a hill, its speed is 10 m/s. Three seconds later, its speed is 32 m/s at the bottom of the hill. What is the roller coasters acceleration? 34. Light from a star travels in a straight line at a constant speed of almost 300,000 km/s. What is the acceleration of the light? 35. A rocket ship is moving through space at 1000 m/s. It accelerates in the same direction at 4 m/s 2. What is its speed after 100 seconds? Hint: (v f =at+v i ) 7

8 Name: 36. How does a speed-time graph indicate acceleration? 37. Use the graph above to answer the questions: a. How would you describe the motion between O and A? b. How would you describe the motion between A and B? c. How would you describe the motion between B and C? 8