Question

an elevator moving downward at 4 m/s experiences an upward acceleration of 2m/s squared for 1.8s. what is the velocity at the end of the acceleration

Answer 1

The final velocity of an elevator

$$v_f=v_i+at$$

$$=4\:\rm m/s+(-2 \: m/s^2)\times 1.8\: s=0.4\: m/s$$