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, , 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, Ax, for these 10 s? (e) Assuming that t=0s 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, Ax, 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?