Question

A stone falls from a ledge and takes 8 seconds to hit the ground. The stone has an original velocity of 0 m/s. How tall is the ledge? A. 313.6 meters B. 78.4 meters C. 1,254.4 meters D. 39.2 meters

Answer 1

The correct answer is letter A. We use the formula,  v=vo + at to get the answer.


v=vo + at 
v=0 + (9.8)(8) 
v=78.4 

y=1/2(vo + v)t 
y=1/2(78.4)(8) 
y=1/2(627.2) 
y=313.6m 

Answer 2

The answer will be A 313.6