Many abbreviations have more than one meaning, ms can be milliseconds or thousandths of a seconds. So, 9.8 ms can mean 9.8 thousandths of a second, or about one one-hundredth of a second.
9.8m/s inidicates a velocity of 9.8 meters every second. However, if you meant 9.8m/s^2, then that is the commonly accepted acceleration due to gravity.
9.8m/s inidicates a velocity of 9.8 meters...