Answer: 6.45 s
Explanation:
We have the following equation:
(1)
Where:
is the height when the rock hits the ground
the height at the edge of the cilff
the initial velocity
acceleration due gravity
time
(2)
Rearranging the equation:
(3)
At this point we have a quadratic equation of the form
, and we have to use the quadratic formula if we want to find
:
(4)
Where
,
, 
Substituting the known values and choosing the positive result of the equation:
(5)
This is the time it takes to the rock to hit the ground
A question you can gather from this experiment is figuring out the distance traveled by the car, and how far it went. A simple solve of X equation could be used.
Answer: The correct answer is B- The ions are free to move in water and carry an electric charge.
Absolute Zero.
Kelvin 0 is Absolute Zero, the atoms cannot physically become any closer.
Celsius -273.15