A ball rolls off the edge of a horizontal roof at 10 m/s. 2 seconds later, the speed of the ball will be? a. 10 m/s b. 19.6m/s c. 29.6 m/s d. 22 m/s ... ?

The ball rolls horizontally thus it is not affected by the gravitational acceleration. We assume that velocity is constant since we are not given acceleration. Therefore, acceleration is zero. The speed of the ball after 2 seconds will still be the same given we have a constant velocity system. Option A is the answer.