Assuming the downward direction to be positive, the acceleration of gravity is about 10 m/s . this means that a) the distance of a falling body increases by 10 m every second. b) the time of a falling body is reduced by one second every 10 m. c) the velocity of a falling body increases by 10 m/s every second. d) the velocity of a falling body increases by 1 m/s every 10 seconds.