Answer:
11 m/s
Explanation:
The motion of the box is a uniformly accelerated motion (=constant acceleration), therefore we can use the following suvat equation:
[tex]v=u+at[/tex]
where:
v is the final velocity
u is the initial velocity
a is the acceleration
t is the time
For the box in this problem, we have:
u = 3 m/s is the initial velocity
[tex]a=2 m/s^2[/tex] is the acceleration
t = 4 s is the time interval
Solving for v, we find the velocity after 4 seconds:
[tex]v=3+(2)(4)=11 m/s[/tex]