Arock 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 answer right !

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).

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

Sorry i dont understand the question can you rephase it?