Two motorcycles are traveling due east with different velocities. However, four seconds later, they have the same velocity. During this four-second interval, cycle A has an average acceleration of 2.1 m/s2 due east, while cycle B has an average acceleration of 3.9 m/s2 due east.
By how much did the speeds differ at the beginning of the four-second interval?
m/s
Which motorcycle was moving faster?