You’re driving in a car along a hilly stretch of highway when you come to a big hill. You decide to measure the height of the hill by coasting up the hill, so you put the car in neutral and coast to the top of the hill. At the bottom of the hill you’re going 28 m/s, while at the top of the hill you are going 17 m/s. How tall is the hill? Is your answer likely to be an over-estimate or under-estimate of the hill’s actual height?