Astudent throws a ball straight down off a very high building with a velocity magnitude of 3.0 m/s the ball accelerated in free fall for 2.0s what is the velocity at 2.0s

In a uniformly accelerated motion, the velocity follows the law:

where v(t) is the velocity at time t, v0 is the initial speed, a the acceleration.
In the free fall motion of the ball, the initial speed is , while the acceleration is the gravitational acceleration: . We take downward as positive direction, so all the signs are positive (because both initial velocity and acceleration point downwards). Replacing t=2.0 s, we find the magnitude of the velocity at t=2.0 s: