This is a picture of a little hill along a road, just a little rise in the pavement. If you don't drive so very slowly, you feel a little lighter, a little "lifted" in your seat as you go over the top of it. (If you drive too fast, you spend a moment in the air!) A. First, without doing any calculations, explain why you feel lifted in your seat. B. Now we're going to come up with an estimate of how much lighter you feel. Suppose the hill is approximately shaped like an arc of a circle that has a radius of 20m. Find the magnitude of the force the seat exerts upward on you, as the moment you're at the top of the bump, expressed as a percentage of your weight.