6. A car goes from 0 m/s to 80 m/s south in 8 seconds along a flat road. (a) What is the magnitude of its average acceleration for the first 8 seconds? (b) Assuming a constant acceleration, a , what is its average speed for the first 8 seconds? (c) How far did it travel in the first 8 seconds? 7. A car's velocity goes from +24 m/s to -20 m/s at a constant acceleration, a , in 10 seconds along a flat straight road. (a) What is its change in velocity? (b) What is its average acceleration, a , for these 10 seconds? (c) What is its average velocity for these 10 s? d) What was its displacement, A x , for these 10 s? (e) Assuming that t = 0 s when the car is going +24 m/s at the beginning of the 10 s interval, at what time did the car stop moving? (f) What distance, A x , did it travel in these 10 seconds? (g) What was its average speed in the first 10s? 8. On Mars, a 15 N (as measured on Mars) vase is dropped out of an apartment window from a height of 40 m onto the cement sidewalk below. When it reaches the pavement, it stops over a distance of 0.5 cm (0.005 m). [Assume: constant acceleration as it fell in free fall and a different constant acceleration as it was stopping. Air resistance is negliglible. Down is positive (+) . The vase does not bounce on the pavement.] (a) How much time did it take for the vase to reach the pavement? (b) How fast (speed) is the vase traveling just before it hits/touches the pavement? (c) What is the average velocity of the vase as it fell - from beginning to just before it hit the pavement? (d) What is the average velocity of the vase as it stopped - from the moment it touches the pavement to being at rest? (e) What is the time it takes to stop - from the moment it touches the pavement to being at rest? (f) What is the acceleration, a , as it stops - from the moment it touches the pavement to being at rest