Final answer:
The dog's acceleration is 1.5 m/s².
Step-by-step explanation:
To find the acceleration of the dog, we can use the formula:
acceleration = (final velocity - initial velocity) / time
Using the given information:
Initial velocity = 10 m/s
Final velocity = 40 m/s
Time = 20 seconds
Substituting these values into the formula:
acceleration = (40 m/s - 10 m/s) / 20 s = 1.5 m/s²
Therefore, the dog's acceleration is 1.5 m/s², so the correct answer is option b).