6. D
7. D
8. B
let me know if you need clarification
Answer:
a= -0.83m\s^2
Explanation:
a = v \ t
a = -25 \ 30 = -0.833 m\s^2
the object is slowing down 0.83 meter every second
D. Speed and direction, this is because velocity is a vector quantity so has a magnitude and direction assigned to it because it is the rate of change of displacement.
Find the average speed and the average velocity.
Average speed = distance / time
distance = 10 x 8000 m = 80,000 m
time = 20 min * 60 s/min = 1200 s
Average speed = 80,000 m / 1200 s = 66.67 m/s
Average velocity = displacement / time
Given that the race car made complete circles the final poin is the same initial point, then its displacement is zero and the average velocity is zero too.