Question

A rock falls off a cliff and hits the ground after three seconds.What is its velocity right before it hits the ground A. 0.31 m/s B. 3.3 m/s C. 9.8 m/s D. 29.4 m/s
PLEASE ANSWER RIGHT AWAY!!!

Answer 1

Hey You!

Vf = Vi + at

Vf = 0 +(9.81 m/s^2) (3 s)

Vf = 29.4 m/s (I believe this should the correct answer if I have done this correctly).

Answer 2

Velocity = 9.8 (gravitational acceleration) multiply by 3 (seconds) 

I presumed gravitational acceleration 9.8. This value is available for tropics. For poles is 9.83 and for equator is  9.78 

Velocity = 29.43

your answer is D