Answer:
4 m/s downwards
Step-by-step explanation:
Velocity is given by dividing the distance by time taken to cover the diatance. Therefore, expressed as v=d/t
The distance is given as 24 m but the time given covers only half the distance. Therefore, the distance is 0.5*21=12 m
Time taken is given as 3 s
Substituting 12 m for d and 3 s for t then
V=12/3= 4 m/s
Velocity must have direction component hence velocity is 4 m/s downwards