posted by Laura .
Your teacher bumps into you in the hallway and knocks you down. After he apologizes, he asks you to figure out how fast he was going. By some magical coincidence, you just happened to be wearing a gauge that measured your mass to be 75 kilograms and your speed to be 25 miles per hour as you were falling. If your teacher has a mass of 85 kilograms, how fast was he going?