1. PA U2C1A8

3. 1. b) Calculate the average speed of the car.

4. 2. Between 0 and 60 s, which toy car has the largest average speed? Car A

5. 3. Which toy car has a constant speed? Car B

6. a) d)b) c)

7. 5. On a hot summer day, an ice-cream truck is cruising along at 15 m/s (34 mph). As the truck enters a residential neighborhood, it takes 4 s to stop. The truck moves 36 m while it is coming to a stop. What is the average speed of the truck while it is coming to a stop? average speed = 36  4

8. 6. Twin brothers Harry and Tim take a long hike through the woods. They walk 3 km east, 4 km north, 3 km west, and 4 km south. The hike brings them back to the same place they started from and takes 4 h. What is Harry and Tim’s average speed during their hike? 3+4+3+4 = 14 4 4

9. 7. An earthquake originates below Earth’s surface. When the P and S waves reach the surface, they cause surface waves, or L waves, to form. From its point of origin on the surface, a surface wave travels through 10 km of granite at 2.5 km/s, and through another 6 km of sandstone at 1.0 km/s, before it reaches and causes damage in a small town. From the time that it forms, the surface wave takes 10 s to reach the town. What is its average speed? 10  6 = 16 10