Answer:
Vo = 18.3 [m/s]
Step-by-step explanation:
To solve this problem we must use the following equation of kinematics.
Vf = final velocity = 0 (the bike stops)
Vo = initial velocity [m/s]
a = desacceleration = 6.42 [m/s²]
t = time = 2.85 [s]
Note: the negative sign in the above equation means that the motorcyclist decrease his velocity.
0 = Vo - (6.42*2.85)
Vo = 18.3 [m/s]