8 th Grade Physical Science Worksheet Part A: Read the scenario and answer the questions. David read that Fox brake pads and Best Brake pads were the best on the market. He always used NAPA pads and believed they performed the best. He decided to test all three pads and determine which was the best. David used the same car for each set of pads. He drove 25 mph and applied the brakes at the same point on the track. David then measured how many feet the car took to stop after the brakes were applied. 1. The hypothesis was: 2. The effects of the (independent variable) on the (dependent variable). 3. List three constants: