From the velocity time graph.calculate: (1) deacceleration in region AB (2) acceleration in region BC (3) total distance travelled in region ABC (4) average velocity between 10 and 30s

From the velocity time graph.calculate: (1) deacceleration in region AB (2) acceleration in region BC (3) total distance travelled in region ABC (4) average velocity between 10 and 30s Ve20cb% (

Dear student,
(i) The deceleration in AB = Decrease in velocity/time taken
                                          $$\begin{gathered} (12-21)/5 \\ = -9/5 \\ =-1.8 m/s^2 \end{gathered}$$

(ii) Acceleration in BC  $$\begin{gathered} (21-12)/15 \\ =9/15 \\ =0.6m/s^2 \end{gathered}$$
(iii) The area of the velocity time graph gives the total distance travelled
       Area of the portion under ABC will be 
Area of rectangle GFDH $$\begin{gathered} =20\times 12 \\ =240 \end{gathered}$$

Area of triangle AGB  $$\begin{gathered} =1/2\times 9\times 5 \\ = 22.5 \end{gathered}$$

Area of triangle BCH  $$\begin{gathered} =1/2\times 15\times 9 \\ = 67.5 \end{gathered}$$

adding all the three we get $$\begin{gathered} 240+22.5+67.5 \\ = 330m \end{gathered}$$

(v) average velocity from 10 to 30 sec is
                  $$\begin{gathered} dis\tan ce travelled/ time \\ =330/20 \\ =16.5m/s \end{gathered}$$
  Regards