The rate of change of velocity V with respect to space S is:

\frac{\pmb{\delta}V }{\pmb{\delta} S}=\frac{12 – 2.4}{3.2}= 3 m/s/m

and the convective acceleration is:

a_{s}=V\frac{\pmb{\delta}V }{\pmb{\delta} S}

Hence at the beginning,

Convective acceleratio a_{2.4}= 2.4 \times 3 = 7.2 m/s^{2}

and at the end,

a_{12}= 12 \times 3 = 36 m/s^{2}