while at soccer practice, abbey runs down the field at 10 meters per second. she has a constant speed and does not change direction. what is abbey's acceleration? a the acceleration is 0 m/s2 because her velocity increased. b the acceleration is 0 m/s2 because her velocity did not change. c the acceleration is 10 m/s2 because her velocity did not change. d the acceleration is 10 m/s2 because her velocity increased.