Final answer:
The acceleration of the dog is calculated by subtracting the initial velocity from the final velocity and dividing by the time taken. The correct answer is 1 mph/s (option A), as the dog's speed changed by 3 mph over 3 seconds.
Step-by-step explanation:
The question asks for the acceleration of a dog when its speed changes from 2 mph to 5 mph over a time interval of three seconds. Acceleration is defined as the rate of change of velocity with respect to time. To find the acceleration, we subtract the initial velocity from the final velocity and then divide by the time over which the change occurred.
In this case, the final velocity (Vf) is 5 mph, and the initial velocity (Vi) is 2 mph. The time (t) taken for this change is 3 seconds. Therefore, the acceleration (a) can be calculated using the formula:
a = (Vf - Vi) / t
Plugging in the values gives us:
a = (5 mph - 2 mph) / 3 s = 3 mph / 3 s = 1 mph/s
So the acceleration of the dog is 1 mph/s, which means the correct answer is A) 1 mph/s.