Use the formula below for this question:

re-arrange to solve for a:

now simply plug in your variables and there's your answer :). If you ever get stuck, you can look up the kinematic equations!
Answer:
Average speed = distance/time
From 1 to 9 seconds:
Distance covered = 1 - 0.2 = 0.8 km
Time = 9 - 1 = 8 sec
Average speed = 0.8 km / 8 sec
Average speed = 0.1 km/s .
The average speed for the whole test is 1.6 km / 20 sec = 0.08 km/sec. A graph of speed vs time would average out as a horizontal line at 0.08 km/sec from 1 sec to 21 sec. The area under it would be (0.08 km/s) x (20 sec) = 1.6 km.
Surprise surprise ! The area under a speed/time graph is the distance covered during that time !
In closing, I want to express my gratitude for the gracious bounty of 3 points with which I have been showered. Moreover, the green breadcrust and tepid cloudy water have also been refreshing.
Explanation:
Answer:
1. F = M x A
2. Force
3. 2nd Law: Force
4. a, b, c (in order)
5. 3rd Law: Action and Reaction
6. b, c, a (in order)
7. 1st Law: Inertia
Energy is the capacity of doing work
Answer:
8.9 g/cm^3
Explanation:
density = mass/volume
volume = length * width * height
volume = (8.4 cm)(5.5 cm)(4.6 cm)
volume = 212.52 cm^3
mass = 1896 g
density = (1896 g)/(212.52 cm^3)
density = 8.9 g/cm^3