The velocity of the chalk after 0.5 s is -2.9 m/s, which means it is moving downward at a speed of 2.9 m/s.
We can solve this problem using the kinematic equation that relates the final velocity of an object to its initial velocity, acceleration, and time:
v_f = v_i + a*t
where:
v_f is the final velocity
v_i is the initial velocity
a is the acceleration
t is the time
In this case, the initial velocity is 2 m/s (downward) and the acceleration is due to gravity, which is approximately 9.8 m/s^2 (downward).
To find the velocity of the chalk after 0.5 s, we can plug in the values into the equation:
v_f = 2 m/s + (-9.8 m/s^2)*(0.5 s)
v_f = 2 m/s - 4.9 m/s
v_f = -2.9 m/s
Therefore, the velocity of the chalk after 0.5 s is -2.9 m/s, which means it is moving downward at a speed of 2.9 m/s.