Answer:
25m/s
Steps:
First, The equation v= u + a * t shows us what we need to find, (the finale velocity).
Second, we substitute the values given:
v= 9m/s + 4m/s2 * 4s
Last, We calculate the values:
Multiply 4m/s2 * 4s = 16m/s
Add 9m/s + 16m/s
Answer: 25m/s
Hope this helps :)