Answer:
Vf = - 3 [m/s]
Step-by-step explanation:
To solve this problem we must use the following equation of kinematics.
where:
Vf = final velocity [m/s]
Vo = initial velocity = - 7 [m/s]
a = acceleration = 1 [m/s²]
t = time = 4[s]
Now replacing:
Vf = -7 + (1*4)
Vf = - 3 [m/s]