Answer :
Given:
The initial speed of the bicycle is,
[tex]u=4\text{ m/s}[/tex]The final speed of the bicycle is,
[tex]v=15\text{ m/s}[/tex]The time interval is,
[tex]t=5\text{ s}[/tex]The acceleration is given as,
[tex]a=\frac{v-u}{t}[/tex]substituting the values we get,
[tex]\begin{gathered} a=\frac{15-4}{5} \\ =\frac{11}{5} \\ =2.2m/s^2 \end{gathered}[/tex]Hence the acceleration is 2.2 m/s^2.