1. The problem statement, all variables and given/known data A bus is traveling at 30.0 km/h speeds up at a constant rate of 3.5 ms/^2. What velocity does it reach at 6.8 seconds later? book says 120.km/hour I get 115 km/hour 2. Relevant equations Vf=Vi+a x delta t 3. The attempt at a solution First I changed 30.0 km/hour to 30000 m/3600s then reduced to 8.3 m/s. Used formula to get Vf=32.13m/s I divide 32.13 by 1000 to get .03213 km/s then 1.9278 km/m then 115.668 km/h. I've worked this problem a hundred different ways and get the same answer. AM i right or the book?