Final answer:
The acceleration of a 20 kg object when a net force of 9.0 N is applied to it is calculated using the formula a = F/m, which results in an acceleration of 0.45 m/s² to the east. The correct answer is A) 0.45 m/s² east.
Step-by-step explanation:
The acceleration of the object can be calculated using Newton's second law of motion, which states that the acceleration (a) of an object is directly proportional to the net force (F) acting on it and inversely proportional to its mass (m), given by the formula a = F/m. In this case, a net force of 9.0 N is applied to a 20 kg object to the east. Thus, the acceleration can be calculated as:
a = F/m = 9.0 N / 20 kg = 0.45 m/s²
Since the force is applied to the east, the acceleration is also toward the east. Therefore, the correct answer is A) 0.45 m/s² east.