Accepted Answer
On Earth, gravity increases the speed of a falling object by about 9.8 m/s every second that it falls.In 0.4 second, its speed increases by (0.4 x 9.8) = 3.92 m/s.If it just rolled off of the shelf at the beginning of that 0.4 second, then it started from zero speed, and its speed after 0.4 second is 3.92 m/s.Its velocity is 3.92 m/s downward.
Suggested Answer
Answer:3.9 m/sExplanation:Apex ; good luck everyone! :)