Answer:
32cm³
Explanation:
Given parameters:
Density of substance = 2.7g/cm³
Mass of substance = 86.4g
Unknown:
Volume of substance = ?
Solution:
Density is the mass per unit volume of a substance.
Density = 
Since the unknown is volume we solve for it;
mass = density x volume
86.4 = 2.7 x volume
volume =
= 32cm³
He answer is A. <span>encourage agricultural usage in the watershed
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where:
F - force
m - mass
a - acceleration
We transform this formula to get a:

I'm guessing that you mean like this:
-- The ruler is held with zero at the bottom, and the centimeter markings
increase as you go up the ruler.
-- You place your fingers with the ruler and the zero mark between them.
-- The number where you catch the ruler is the distance it has fallen.
Then, all we have to find is the time it takes for the ruler to fall 11.3 cm .
Here's the formula for the distance an object falls from rest
in a certain time:
Distance = (1/2) (gravity) (time)²
On Earth, the acceleration of gravity is 9.8 m/s².
So we can write ...
11.2 cm = (1/2) (9.8 m/s²) (time)²
or
0.112 meter = (4.9 m/s²) (time)²
Divide each side
by 4.9 m/s² : (0.112 m) / (4.9 m/s²) = time²
(0.112 / 4.9) sec² = time²
Square root
each side: time = √(0.112/4.9 sec²)
= √ 0.5488 sec²
= 0.74 second (rounded)