Answer:
a = 0.273 m/s²
Step-by-step explanation:
I would assume that the rider starts at 0m/s.
a = average acceleration
v = final velocity = 3 m/s
v0 = initial velocity = 0 m/s
t = time = 11 s
a = (v-v0)/t
a = (3m/s - 0m/s) / 11s
a = 0.273 m/s²
I am not sure how many decimals I should round it to, so I just gave three. If your teacher has instructions on that, do so accordingly.