Answer:
See below ~
Step-by-step explanation:
<u>Part 1 - Acceleration when t = 3</u>
- Acceleration is constant during the time period t = 0 to t = 4
- a = change in velocity / change in time
- a = 22 - 11 / 4 - 0
- a = 11/4
- a = <u>2.75</u> m/s²
<u>Part 2 - Deceleration when t = 12</u>
- Deceleration is constant during the time period t = 8 to t = 15
- Distance covered in the time period = 1/2 x 7 x 22 = 77 m
- v² - u² = 2aS
- 0 - 484 = 2(77) × a
- a = -484/154
- a ≈ <u>-3.14</u> m/s²
<u>Part 3 - Total Distance Covered</u>
- Area under the graph gives distance
- <u>From t = 0 to t = 4</u>
- S = 1/2 x 11 x 4 + 11 x 4
- S = 22 + 44 = 66 m
2. <u>From t = 4 to t = 8</u>
3. <u>From t = 8 to t = 15</u>
Total distance = 66 + 88 + 77 = <u>231</u> m
<u>Part 4 - Average Speed</u>
- <u>Avg. Speed (t = 0 to t =4)</u>
2. <u>Avg. Speed (t = 4 to t = 8)</u>
3. <u>Avg. Speed (t = 8 to t = 15)</u>
Average Speed = 16.5 + 22 + 11 / 3