Final answer:
The purpose of using a protractor hanging from a car to measure acceleration is to determine the change in velocity over time, which is a measure of acceleration. The methodology involves attaching a protractor vertically to a car and measuring the angle of incline as the car accelerates.
Step-by-step explanation:
The purpose of using a protractor hanging from a car to measure acceleration is to determine the change in velocity over time, which is a measure of acceleration. The protractor measures the angle of incline, which can be used to calculate the acceleration using trigonometry. The methodology involves attaching a protractor vertically to a car and measuring the angle of incline as the car accelerates.