Answer:-
-1 m/s^2
Step-by-step explanation:
The average acceleration is given by dividing the change in velocity by change in time;
![a_f=(v_f-v_i)/(t_f-t_i)](https://img.qammunity.org/2021/formulas/physics/college/bvqn2f1j15yny5g7xvo0rd9t3we3lzyigw.png)
![=((0-11.2))/((11.2-0))=-1 m/s^2](https://img.qammunity.org/2021/formulas/physics/college/6d97o9eftd8uu76f8pn5f3atpbh421hojm.png)
the point to be noted here is if the velocity is to the left we substitute it with a negative sign and if it is to the right we substitute it with a positive sign.